From unRAID
This guide is intended to get you from a completed and working flash drive to a usable array.
Note: written for version 4.5.6
valid for version 4.6
valid for version 4.7
Note: These instructions assume the use of a Windows computer,
but if you don't have access to one, the instructions are
basically the same for Linux or Unix-based operating systems.
The following assumptions are made:
You have 'installed' unRAID to your flash drive. If you have not, please see the
and do so now.
You are familiar with (or will become familiar with) .
You know what a command prompt is and how to access it.
You have a basic understanding of computer networking concepts.
You don't need to be a network administrator, but if you don't know what an IP address is you should spend some time on google!
If you are unclear about any of those, read the linked articles/guides, perform your own research, and ask questions in the .
Note: If you are in a hurry you may skip copying the preclear_disk.sh
and the unmenu_install scripts to your flash drive.
The preclear
script is used to test your disks and prepare them for the unRAID
environment.
The merits of preclearing are discussed in this
The unmenu_install script is used to install
will allow the installation of Screen.
Installing screen will allow
you to start a process (such as a preclear) in a telnet session, then
disconnect the telnet session and allow the process to continue.
you do not mind keeping a telnet session open for potentially days or
you run commands directly from the console, skipping
and Screen
Installing UnMENU will also allow configuration of the environment to
allow the preclear script to send email notifications of its status.
Before booting your unRAID system you need to copy a few files to your flash drive.
The preclear_disk.sh script will enable you to prep your disks for the array and the unmenu_install script will install .
Step 1 From a non unRAID system download the preclear_disk.sh script from this .
The download is at the bottom of the first post
You must be logged into the forum to see the file
Unzip the file and copy preclear_disk.sh to the root of your flash drive.
Step 2 Download the unmenu_install script from the
and unzip the file on your PC.
Create a folder named unmenu in the root of your flash drive.
Copy unmenu_install to the unmenu folder on your flash drive.
Now that you have the required files on your flash drive, use it to boot your UnRAID system.
When the system has been booted you will be greeted with a prompt similar to
Welcome to Linux 2.6.32.9-unRAID (tty1)
Tower login:
Type root and press enter to log into the system.
The prompt should change to
root@Tower:~#
which is hereafter referred to as the prompt.
To verify that your UnRAID system is connected to the network, at the prompt type enter
ifconfig eth0
This will present quite a bit of information, however, the only line we are interested in is the one containing
inet addr:192.168.1.123
The IP address (numbers) after inet addr will almost certainly be different, but anything that has 192.168.x.x or 10.x.x.x means your UnRAID server received an IP address from a DHCP server and is connected to the network and is ready to go.
If there is nothing after inet addr make sure your network cable is connected, and you have a router or other DHCP server on your network.
If you do not have a DHCP server you need to set your network settings manually.
Note your IP address now, you may need it shortly, and skip to the next section, or continue to the next section to set a static IP address.
If you do not have a DHCP server on your network, you must manually set an IP address for your UnRAID server.
By default, the only two text editors installed with UnRAID are "vi" and "mcedit." If you are not already familiar with "vi" it is suggested you use "mcedit" as it is much easier for a beginner.
If you wish, the editing can be done on your windows PC instead.
To do that, shutdown the UnRAID server by typing
shutdown -h now
at the prompt and pressing enter.
Note: the "shutdown -h" command DOES NOT cleanly stop the array.
If you type this on an array with a configured parity drive it will force a full parity calculation when you reboot.
Then remove the flash drive and open the network configuration file on another computer using Notepad or another text editor you are familiar with.
To open the network configuration file with mcedit, at the prompt type
mcedit /boot/config/network.cfg
If using "putty" as your telnet client program on your PC, the function keys and mouse will work in "mcedit"
If not using "putty", you can use The Escape key followed by the number 1 through 0 to simulate function keys 1 through 10.
You will need to use function key F2 to save your edited file, and F10 to quit the editor.
(or Escape 2, Escape 0)
To open the network configuration file with vi, at the prompt type
vi /boot/config/network.cfg
To open the network configuration file on a separate computer it will be located at
D:\config\network.cfg
Replace D: with whatever drive letter the flash drive is mounted as and open the file with a text editor.
By default the file will contain:
USE_DHCP=yes
This should be changed to reflect your environment.
A typical configuration could be
USE_DHCP=no
IPADDR=192.168.1.150
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
USE_DHCP should be set to no
IPADDR should be set to an unused IP address that is in the same subnet as your other computers.
NETMASK is network dependent, but in most cases will be 255.255.255.0 or 255.0.0.0.
Check the network settings on an existing computer on your network if you are unsure.
GATEWAY is the default gateway to the internet on your network.
Again, network dependent.
Check the settings on an existing computer if you are unsure what to use for your environment.
This may be left blank, but that will prevent the UnRAID server from passing traffic outside the subnet in which it resides
To enable these settings save the file and restart the UnRAID server.
If you used vi or mcedit to edit the file, after exiting the editor execute
shutdown -r now
to reboot the system.
If you edited the file on another computer.
Remove the flash drive and re-attach it to the unRAID server and power it back up.
Note: This section assumes all SATA hard drives!
If you are using older hardware,
or have the disk controller configured in a legacy compatible mode (emulating an IDE disk controller)
these messages will not exist.
To verify that your SATA hard drives are detected as SATA devices, at the prompt type
dmesg|grep SATA|grep link
You should get a listing of each SATA controller, its link status, and its speed.
The output will look similar to
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata4: SATA link down (SStatus 0 SControl 300)
ata5: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata6: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
In this example there are 6 SATA controllers with 5 drives connected at 3.0 Gbps.
Make sure your output matches your hardware ie if you have 5 drives connected, make sure you see 5 drives here and the link speeds are correct.
Now that you have verified your UnRAID server can see the network and its hard drives are connected correctly it's time to log into the web interface and continue setup.
Using another system that is connected to your network, open a web browser and in the address bar type
This should take you to the server management page.
If it does not try entering
//IP_ADDRESS
where IP_ADDRESS is the IP address you noted earlier.
If you are having trouble connecting, there are more details available in the .
Once you have connected to your server, navigate to the settings page by clicking settings in the navigation bar at the top of the server management page.
Server Name - This is the name that your server will be known as on the network.
It must be a unique name not in use on your network.
Set yours to whatever makes you happy.
Comments - The comments entered here will show up next to the server name under My Network Places.
Again, whatever makes you happy.
Share security - this is the security model used to control access to the server.
Leave as Simple for now.
Security will be covered later in the tutorial.
Workgroup - This is the Windows Workgroup your server will belong to.
Set this to the same Workgroup that your Windows computers belong to.
Local master - If set to yes UnRAID will attempt to become the local browse master
Probably un-necessary on a small, single subnet network.
Set to No unless you have problems browsing to your server
More information from
If you have made any changes to these settings click apply.
If you changed the server name and were connected to the Server Management Utility using //tower you may need to type //NEW_SERVER_NAME to re-connect.
Obtain IP Address Automatically - When set to yes the server will obtain an IP address from a DHCP server on the network.
This has the benefit of set it and forget it but the IP address may change between reboots.
Set to yes unless you know you need to assign a static IP address to your server.
IP Address - Set a static IP address for the server.
Not available unless Obtain IP Address Automatically is set to No.
Set as appropriate for your network.
Netmask - Subnet information.
Not available unless Obtain IP Address Automatically is set to No.
Set as appropriate for your network.
Gateway - Default gateway/router.
Not available unless Obtain IP Address Automatically is set to No.
Set as appropriate for your network.
Obtain DNS Server Address - Get DNS servers from DHCP or not.
If you have Obtain IP Address Automatically set to yes, you probably want this set to yes as well.
If not you need to manually assign your DNS servers.
DNS Server 1..3 - You can assign up to 3 DNS servers for name resolution.
Not available unless Obtain DNS Server Address is set to No.
If you have made any changes to these settings click apply.
If you changed the IP address you will need to reconnect to your server using the new IP address.
If you are using Windows and were connected using //tower (or a new name if changed) open a command prompt and type
ipconfig /flushdns
nbtstat -R
to clear the resolver cache and force the computer to re-query the network for the new name.
Time zone - Sets the time zone for the server.
Set as appropriate for your location.
Use NTP - Use network time protocol to set the server time based on a remote time server.
Highly recommended to set this to yes.
NTP Server 1..3 - You can configure UnRAID to use specific time servers.
These options are only available if Use NTP is set to Yes.
The default pool.ntp.org is recommended.
More information from
Current date & time - Set the current date and time.
If Use NTP is set to Yes, this is irrelevant and NTP will set everything.
IF you are not using NTP you need to set your time and date here in UTC time (FIX ME IF I'M WRONG!!!!!)
If you made any changes here, click Apply.
One thing I noticed was that the time did not update and display correctly until after I rebooted the server so if things don't look quite right, wait until after the next reboot to panic.
Default spin down delay - Set the amount of time without activity to wait before spinning down disks to save power.
Tweak as appropriate for your environment.
If set too short you will find yourself waiting for disk spinups.
If set too long you will waste power.
Force NCQ disabled - Disable native command queuing.
Recommend leaving this as yes.
Disable NCQ on all disk devices that support NCQ.
This typically results in much better write throughput.
A setting called "Force NCQ disabled [yes/no]" is also available in the Disk section of the Settings page of the System Management Utility to override this new behavior.
That is, if this setting is 'yes', then we force NCQ if setting is 'no', we leave NCQ queue_depth as-is, ie, whatever linux driver sets it to.
Enable spinup groups - Allow disks to be spun up/down in appropriate groups.
Recommend leaving this as yes.
Good information available .
If you made any changes here, click Apply.
At this point it is recommended that you reboot the server.
To do so, click Main then click the reboot button to restart the server.
It is not required to install UnMENU and Screen or eMail notifications, you may skip all or part(s) of this step if you are in a hurry and do not mind running the preclear_disk.sh from the console of the UnRAID server or leaving a telnet session open for an extended period.
Once you installed unMENU it is highly recommended to install the . Sometimes the GUI will go unresponsive which renders you without a possibility to cleanly powerdown the server! This script will bypass the GUI and facilitate a clean shutdown.
Install the powerdown upgrade in the same way as
is installed.
is an enhanced Web management page for unRAID that provides a number of user-requested features, and is relatively easy to extend.
Installing it now gives you access to screen and email notifications, both of which are useful for preclearing hard drives.
Note: This step assumes have the unmenu_install script on your flash
for details
if you do not.
Note: For this step your server must have access to the internet to
download some files.
It is NOT recommended that you connect
your UnRAID server directly to the internet as it is not secure.
You should connect your unRAID server to a router that in turn is
connected to the internet.
To be able to download files you must
have both a DNS server and a Gateway defined on the unRAID
web-management settings page.
Typically both will be set to the
IP address of your router.
Step 1 Log into your UnRAID server as root via a telnet connection or at the console.
Step 2 At the prompt type
cd /boot/unmenu
Step 3 At the prompt type
./unmenu_install
-i -d /boot/unmenu
The script will download the files needed and place them in the appropriate location.
Step 4 To start UnMENU, at the prompt type
You will be dumped right back to a prompt, this is normal.
Step 5 To enable UnMENU to run on reboot, at the prompt type
echo "/boot/unmenu/uu" && /boot/config/go
if it is not already installed.
Step 2 From another computer on the network open a web browser and navigate to
//tower:8080
Substitute your server's name or IP address for tower.
Step 3 At the top of the screen select Pkg Manager.
Step 4 Scroll down (close to the bottom) and click Select screen-4.03-i486-1.tgz.
Step 5 Click Download screen-4.03-i486-1.tgz.
The status will change to "Package downloaded, but not yet installed".
Step 6 Click Install screen-4.03-i486-1.tgz.
You will see a report of the commands run and the status will change to "screen-4.0.3-i486-1.tgz is now installed".
Step 7 Click Enable Re-Install on Re-Boot so screen will be re-installed on every reboot.
if it is not already installed.
Step 2 From another computer on the network open a web browser and navigate to
//tower:8080
Substitute your server's name or IP address for tower.
Step 3 At the top of the screen select Pkg Manager.
Step 4 Scroll down to "C" compiler & development tools and click the Select gcc-4.2.4-i486-1.tgz button.
Step 5 Click Download gcc-4.2.4-i486-1.tgz. The status will change to "Package downloaded, but not yet installed".
Step 6 Click Install gcc-4.2.4-i486-1.tgz. You will see a report of the commands run and the status will change to "gcc-4.2.4-i486-1.tgz is now installed".
Step 7 Return to the Pkg Manager page by clicking on View All Available Packages button at the top of the screen.
Step 8 Scroll down to mail and ssmtp- Configure unRAID to be able to send e-mail notifications via the "mail" command. and click on the Select ssmtp_2.62.orig.tar.gz button.
Step 9 Click the Edit Configuration Variables button at the bottom of the page and edit the values as appropriate for your mail server.
Forward "root" email to:
[] Enter the e-mail account where mail to root will be forwarded.
E-Mail Server:
[] Mail Server Address used to send e-mail.
Use TLS?(YES/NO):
[] If using a secure connection to the mail-server, set this to YES.
[] Your e-mail account on the mail server. (just the ID without the @)
Needed if your mail server requires authorization, leave blank otherwise.
Mail Password:
[] The e-mail password used when SENDING e-mail. (sometimes different than the
one used to read mail) Needed if your mail server requires authorization,
leave blank otherwise.
Mail Domain:
[] Mail originates from this domain. (For many E-mail servers you can use
"localhost", for gmail you can use "")
From Line Override (YES/NO): [] Make message appear to originate from mail server.
[] If non-blank, make mail appear to come from domain. (Some mail hosts will not
allow the mail to appear from elsewhere, so leave this blank unless you need
to specify an alternate domain of origin)
Step 10 Click the Save Vew Values button.
Step 11 Click Download ssmtp_2.64.orig.tar.bz2. The status will change to "Package downloaded, but not yet installed".
Step 12 Click Install ssmtp_2.64.orig.tar.bz2. You will see a report of the commands run and the status will change to "ssmtp_2.64.orig.tar.bz2 is now installed".
Step 13 Click Enable Re-Install on Re-Boot so "mail and ssmtp" will be re-installed on every reboot.
Step 14 Test the installation.
Log in as root at the console or in a telnet session to the UnRAID server and at the prompt type
echo -e "Subject: a test\n\nThis is the email body." | ssmtp -d root
This will send a test message to the email address specified in step 9.
It is also possible to easily install screen without first installing UnMENU by downloading the slackware packages required and following the steps below:
Get the screen and utempter packages from the .
If you are intending to use screen with unRAID v5 then you need the Slackware 13.37 versions (which are 32-bit) and for unRAID v6 you need the Slackaware64 Current versions (which are 64-bit versions).
Copy these files onto your USB drive.
The easiest way to do this is to copy them to the Flash share over the network.
The Flash share is available by default (although it is possible to disable it via the unRAID GUI settings for the Boot device).
The recommended place to put them is in an extra folder (creating it if it does not exist).
If you put the downloaded package files in the extra folder as recommended then these packages will be automatically installed by unRAID every time the server is booted.
You can also install the packages manually from a telnet session. It can be convenient to do this when you have just downloaded the packages to avoid the need for a server reboot.
It is also the way to go if you do not want the screen package to always be automatically loaded and want to do it yourself manually as required. The manual install is done by using a command of the form:
installpkg name_of_package_file
Screen is now available as a standard plugin on the forum
Pre-clearing is a process for carrying out confidence checks on drives, and speeding up adding new drives to an existing parity protected array.
If you intend to pre-clear a drive then (s), but do not assign the drive(s) to the array. Pre-clearing is optional, but . Preclearing takes a
. If you can afford the time then to have maximum confidence in the integrity of a drive it is recommended that you should run
on new drives. One or two passes on previously precleared drives (another system, or moving drives around) should be fine. JoeL wrote the .
sdX drives are SATA and SCSI. hdX drives are IDE.
This is the preferred method if you are using a telnet session.
The reason is that if you are running pre-clear via a telnet session then if the telnet window gets closed before the pre-clear finishes then the pre-clear is aborted. Since a pre-clear on large disks can take days to complete then having a session accidentally aborted and having to start again is not something that one wants to have to do.
If you are running pre-clear under screen then the pre-clear is NOT aborted if the telnet window closes, and you can later rec-connect via telnet to find out how the pre-clear has progressed.
Step 1 Open a telnet session to your UnRAID server and login as root.
Step 2 To navigate to the preclear script, at the prompt type
Step 3 At the prompt type
Depending on the version of Screen installed, an information screen may show up.
If you see
bash: screen: command not found
you need to
If you see
Cannot find terminfo entry for 'vt100'
it indicates your telnet client's emulation is not compatible with screen.
Try a different emulation type or use Putty, which works well with screen.
If you invoke screen and it shows an introductory page, press Space or Return to continue and you will be returned to the prompt.
Now that you are running inside a "Screen" you can create multiple prompts and even disconnect from your telnet session and processes will continue to run in the background.
If you get Screen running, or get no errors, move to Step 4.
Step 4 Identify the drive to be pre-cleared. Run this command (from the /boot dir)
preclear_disk.sh -l
The -l is a L as in LIST. The output will look like this:
preclear_disk.sh -l
====================================1.13
Disks not assigned to the unRAID array
(potential candidates for clearing)
========================================
/dev/sda = ata-STCH166_W1F293RJ
Make a note of the /dev/sdX or /dev/hdX. This is the drive you're going to be clearing.
Step 5 To begin the preclear on a drive, at the prompt type
./preclear_disk.sh -A /dev/sdX
If you wish to run multiple cycles of the preclear script on the drive to exercise it,type
./preclear_disk.sh -A -c 3 /dev/sdX
where sdX is the device mapping of the drive you want to preclear, and 3 is the number of cycles you want to run.
Note: If you have only SATA drives and see a /dev/hdX device it
indicates you have set your motherboard BIOS to have it
emulate an older IDE drive to the operating system.
is NOT desired for SATA drives since they will not be
able to use any of their more advanced features.
instead want ACHI mode, not legacy mode.
Note: If you are pre-clearing a WD EARS drive that has had a jumper installed to electrically
add one to a sector when accessed, then use the "-a" option to the preclear script
rather than the "-A" option.
This is ONLY for that one specific make/model drive
and ONLY IF it has a jumper added.
For ALL other drives, or the WD EARS without a jumper, use the "-A" option.
If you are pre-clearing multiple drives it is recommended you also use the optional "-r" "-w" and "-b" options.
These set the size and number of blocks of data read and written to the disks during processing.
Although not needed when clearing a single drive, If you do not use these options the preclear script may run out of memory when concurrently processing multiple large drives.
Suggested values are
preclear_disk.sh -r 65536 -w 65536 -b 2000 -A /dev/sdX
"-r NNNNNN" sets the size of the read blocks, "-w NNNNNN" sets the size of the written blocks, and "-b NNNNN" sets the number of blocks read in each operation.
If you installed
and wish to have email notifications of the process, instead of the above type
./preclear_disk.sh -A -M 4 /dev/sdX ("root" email address) or
./preclear_disk.sh -A -m
/dev/sdX (optional email address)
Put your email address and sdX is the device mapping of the drive you want to preclear.
If this is an IDE device it will be hdX.
Note: if you do not supply either a "-a" or "-A" option, the preclear_disk.sh script will use the setting
you've elected in the unRAID "settings" screen as its default partition type.
It is recommended you set this to MBR-4k-aligned.
-a will override the default and create an MBR-un-aligned partition starting on sector 63.
-A will override the default and create an MBR-4k-aligned partition starting on sector 64.
Neither option is recognized for disks & 2.2TB.
They will always be 4k-aligned using a GPT partition.
If the -a or -A option is given on a drive over 2.2TB, it is silently ignored and no harm is done.
Disks over 2.2TB will also have a "protective" partition starting on sector 1 added to the MBR
to be compatible older programs and utilities and show they are entirely allocated.
This will present you with a screen similar to
Pre-Clear unRAID Disk
########################################################################
Device Model:
WDC WD20EARS-00J2GB0
Serial Number:
WD-WCAYYXXXXXXX
Firmware Version: 80.00A80
User Capacity:
2,000,398,934,016 bytes
Disk /dev/sde: 2000.3 GB, 6 bytes
255 heads, 63 sectors/track, 243201 cylinders, total
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x
Device Boot
Partition 1 does not end on cylinder boundary.
########################################################################
Are you absolutely sure you want to clear this drive?
(Answer Yes to continue. Capital 'Y', lower case 'es'):
Double check to make sure the Drive model and/or serial number are what you expect.
If everything is copacetic type "Yes" and press enter like the box tells you too.
When you do, EVERYTHING on the drive will be DELETED.
The screen will clear when you respond with 'Yes' and be replaced with one showing progress and automatically updating at regular intervals.
This will allow you to track the progress of the clearing of the drive.
Step 6 You can preclear multiple drives at once using multiple Screen sessions. Once you've gotten the first drive preclearing, start up the next one by pushing
That translates to hold down the Control key and press the A key.
Release both keys then press the c key.
This creates a new screen inside Screen and gives you a new prompt.
Start the preclear for this drive just like the preclear for the first one.
You can create a new screen for each preclear you need to run, however, it is not recommended to run more than 4 at once.
Step 7 Now that the preclears are running to cycle through them and check on their status press
This will take you to the next screen and will loop back to the beginning when you reach the end.
To go to the previous screen press
It will loop back to the end when you reach the beginning.
You can keep your telnet session open to keep tabs on the progress and if you accidentally get disconnected the processes will remain running.
You can also manually disconnect from your session by typing
you will be returned to the prompt with a message that screen has detached.
At this point you can terminate your telnet session.
At a later time you can establish a new telnet session and reattach to Screen to check on the status of your preclears.
Step 8 To reattach to the Screen, log in via telnet or on the system console as root.
At the prompt type
This will take you to your first screen and you can cycle through as noted above.
Step 9 When your preclears have finished there will be a message on the screen that the drive either successfully passed or failed the preclear process as well as a diff of the pre and post SMART reports.
There is some information in this
on how to interpret the results of the diff.
Also if you have questions about your result the appropriate place to ask them is in
See below for instructions on saving the results.
Specifically look for increases of the "raw" count of re-allocated sectors and sectors pending re-allocation.
Most of the other "raw" values are meaningful only to the manufacturer of the disk drive.
If your diff report is long some of it may have scrolled off the screen.
To see it press
You will get a notice at the bottom of the screen that you are in copy mode.
Now you can use the Page up and Page down keys to scroll up and down and view the results.
Press Esc to exit copy mode.
Step 10 As your drives finish preclearing, you can close their screens by pressing
to logout of that screen. or you can simply type
You will then be taken to the next or the previous screen in the buffer.
When the last drive finishes and you close its screen you will get a message that screen is terminating.
At this point it is recommended that you save your preclear results for future reference or so you can post them to the forum if you have any questions regarding the results.
The preclear results are automatically saved for you in the /boot/preclear_reports directory.
Each disk successfully pre-cleared will have three files, the SMART report at the beginning of the process, a SMART report at the end of the process, and a summary report comparing the two to make it easier to see and interpret the differences.
These files can be easily attached to a forum post if you are unsure of how to interpret the results.
To save your results as a single MS-Dos text file, at the prompt type
grep preclear /var/log/syslog | todos && /boot/preclear_results.txt
This will save all the relevant lines from the syslog to the preclear_results.txt file on your flash drive.
You can then copy this file to another computer and peruse your results or post them to the forum.
Don't preclear without screen.
If you did not install screen, you can preclear your hard drives from the console.
Linux provides 6 Virtual Terminals (V-Terms) that you can use from the console.
It is possible to run a preclear in a telnet instance, however it is not recommended because if your session is interrupted, the preclear process will be terminated.
If you wish to take that risk, you can substitute each Vterm with a new telnet session.
Step 1 Log in to your UnRAID server as root at the console
Step 2 To navigate to the preclear script, at the prompt type
Note: If you are preclearing any AF drives, be sure to use the -A option
when you invoke the preclear script.
i.e replace
./preclear_script.sh /dev/sdX with ./preclear_script.sh -A /dev/sdX
Note: Drives greater than 2.2TB in size automatically use a GPT partition that
is always aligned on a 4k boundary.
The "-a" and "-A" options on the
preclear script are ignored on those drives & 2.2TB as those options
only apply to drives &= 2.2TB.
Step 3 To begin the preclear on the 1st drive, at the prompt type
./preclear_disk.sh /dev/sdX
where sdX is the device mapping of the drive you want to preclear.
If this is an IDE device it will be hdX.
If you installed
and wish to have email notifications of the process, instead of the above type
./preclear_disk.sh -m
-M4 /dev/sdX
Put your email address in and substitute for sdX the device mapping of the drive you want to preclear.
If this is an IDE device it will be hdX.
This will present you with a screen similar to
Pre-Clear unRAID Disk
########################################################################
Device Model:
WDC WD20EARS-00J2GB0
Serial Number:
WD-WCAYYXXXXXXX
Firmware Version: 80.00A80
User Capacity:
2,000,398,934,016 bytes
Disk /dev/sde: 2000.3 GB, 6 bytes
255 heads, 63 sectors/track, 243201 cylinders, total
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x
Device Boot
Partition 1 does not end on cylinder boundary.
########################################################################
Are you absolutely sure you want to clear this drive?
(Answer Yes to continue. Capital 'Y', lower case 'es'):
Double check to make sure the Drive model and/or serial number are what you expect.
If everything is copacetic type "Yes" and press enter like the box tells you too.
When you do, EVERYTHING on the drive will be DELETED.
Step 4 Now that the first preclear is running, to start the next one press
to go to Vterm 2.
You can repeat steps 1-3 to start the preclear on the next hard drive.
To get to Vterm 3 press
You can use this to access 6 Vterms by using F1-F6.
The preclear script in each Vterm runs independently and you can keep an eye on the process of each one by switching back and forth with Alt-Fx.
Step 5 When your preclears have finished there will be a message on the screen that the drive either successfully passed or failed the preclear process as well as a diff of the pre and post SMART reports.
There is some information in this
on how to interpret the results of the diff.
Also if you have questions about your result the appropriate place to ask them is in
See below for instructions on saving the results.
If your diff report is long some of it may have scrolled off the screen.
To "scroll up" to see it you can use Shift-Page up and Shift-Page down to scroll around in the buffer.
Step 6 As your drives finish preclearing, you can close their Vterms by pressing
to logout of that Terminal or by typing
at the linux prompt.
At this point it is recommended that you save your preclear results for future reference or so you can post them to the forum if you have any questions regarding the results.
Step 7 After all preclears have finished to save your results, at the prompt on Vterm 1 (Alt-F1) type
grep preclear /var/log/syslog | todos && /boot/preclear_results.txt
This will save all the relevant lines from the syslog to the preclear_results.txt file on your flash drive.
You can then copy this file to another computer and peruse your results or post them to the forum.
Adding drives to the array is simply a matter of telling UnRAID which drive to place where during initial setup.
Later as you add drives to the array after enabling a parity drive, each drive must have zeros written to every sector before the drive is accepted into the array.
UnRAID will
however, the array will be taken offline for the entire process which can take quite awhile. ( 20 hours or more for a 2TB drive ) To prevent this, you can run the preclear_disk.sh script on a new drive before you add it to the array and UnRAID will recognize that the drive already has zeros written to every sector and will only take the array offline long enough to perform a format which only takes a minute or two.
Disks that do not have unRAID compatible partitions will be re-partitioned immediately upon assignment to the array. (In other words, do not assign disks from other OS with data you wish to retain)
Note: The parity disk must be as large or larger than the largest data drive.
Remember to leave one of the largest drives free to use as a parity drive.
Step 1 On another computer (not your unRAID system) open a web browser and navigate to the .
Then click on Devices.
Step 2 Click the drop down box next to disk1 device and select a disk to assign to this position.
Step 3 Repeat this process for each disk that you want to add to the array as a data storage disk and add them under disk2 device, disk3 device, etc.
Note: At this point you have to choose whether to add your parity drive now or later.
If you wait to add a parity drive later, copying initial data to the array
will be much faster, but the data will not be protected from a single disk
If you do add a parity drive, you will be protected from a single
disk failure from this point forward, but writes to the array will be much
slower due to parity calculations. If you add a parity drive now an initial
parity calculation will begin when you start the array.
Step 4 To add a parity drive, click the drop down box next to parity device and select a disk to be used for parity.
To assign a parity drive later, leave the parity device unassigned.
Note: If you intend to work with shares, you may first want to enable them prior
to starting the array since enabling shares requires the array to be
in an offline state.
Otherwise, you will either have to stop the array (and
potentially a parity rebuild) to enable shares.
Note that once user shares are
enabled, you can create shares while the array is online.
Step 5 After all drives have been added to the array click Main on the navigation bar at the top of the page, then click Start to start the array.
When initially adding a parity drive to an array, a parity sync must be performed.
For an array containing a large amount of data, this can be a time-consuming process, and the array's performance may degraded during the entire sync as the process involves reading every sector of the data drives and writing the entire parity drive.
You may use the array during this initial parity calculation.
Step 6 Before you can use the array you must format any data drives you have assigned to the array.
After you start the array any newly added data drives will show as Unformatted on the web-management interface.
There will also be a Format button on the bottom third of the screen.
You must press it to format the newly added data drives before you can use them to store your data.
You do that by pressing the Format button.
Note: if any drives show as unformatted, but are known to have already been formatted, and already hold your unRAID data, do not press the Format button.
Seek guidance on the unRAID forum.
Formatting typically only takes a few minutes per drive if they have been .
If the data disks are not pre-cleared, and you've already assigned a parity drive, unRAID will proceed to clear the new data drives prior to formatting them.
This can take 8 or more hours () for a 2TB drive.
During this time the unRAID array will be off-line and unavailable for use.
(It is one reason why pre-clearing is so popular.
It permits unRAID to skip this lengthy clearing process prior to formatting)
After the initial parity calculation is complete, it is highly recommended to perform a manual parity check.
This is to test you can read the parity data just written to the parity disk.
To perform a manual parity check click on the Check button on the main web-management page at
in your browser.
The process of initially calculating parity or checking parity will run at a speed somewhere between 10MB/s and 100MB/s.
(Older PCI based motherboards with large numbers of drives will likely be under 15MB/s.
Newer SATA PCIe based systems will get between 60 and 100MB/s.)
The speed will be faster on outer cylinders of the disk drives, and slower on the inner cylinders, therefore, expect the speed to slow down over time.
At this point skip over the next section and configure your User shares, but be sure to come back to it if you are waiting until your array is populated to add the parity drive.
When adding a parity drive to an un-protected array, a parity sync must be performed.
For an array containing a large amount of data this can be a time consuming process and the array's performance will degraded during the entire sync as the process involves reading every sector of the data drives and writing the entire parity drive.
You may use the array during this initial parity calculation.
Step 1 Stop the array.
Step 2 Click Devices.
Step 3 Select the drive to be used for parity from the drop down menu next to parity device.
Step 4 Click main, place a check in the box next to I'm sure I want to do this, and then click Start.
Step 5 Click refresh after a few moments to see the status.
This will give you the statistics of the Parity-Sync along with an estimated finish time.
After the initial parity calculation is complete, it is highly recommended to perform a manual parity check.
This is to test you can read the parity data just written to the parity disk.
To perform a manual parity check click on the Check button on the main web-management page at
in your browser.
The process of initially calculating parity or checking parity will run at a speed somewhere between 10MB/s and 100MB/s.
(Older PCI based motherboards with large numbers of drives will likely be under 15MB/s.
Newer SATA PCIe based systems will get between 60 and 100MB/s.)
The speed will be faster on outer cylinders of the disk drives, and slower on the inner cylinders, therefore, expect the speed to slow down over time.
You can copy data to either configured shares or disk shares during the parity rebuild process.
Parity will be updated on the fly for new files that are written to the array.
It's important to note, however, that until the parity rebuild process is complete, data existing on the array is not protected.
Shares are the primary, and coolest method of accessing data stored on the UnRAID server. This abstracts your data from specific drive mappings and allows easy access to your data on the network in a simple manner. No matter what mish-mash of hard drives you have in your server, enabling and using Shares makes it seem that you simply have one giant drive available in your Network Neighborhood. More details on user shares are available in the . Some users choose not to use User Shares and if that is your preferred method, leave User Shares disabled and access your data using only the disk1..diskn mappings configured in the
Step 1 On another computer (not your UnRAID system) open a web browser and navigate to the .
Then click on Main and stop the array if it is already started.
Step 2 Click Shares, set User Shares to enabled, then click apply.
Step 3 Click Main, then click Start to start the array.
Step 4 Click Shares to edit the shares properties.
Each share can be set to one of five different SMB export modes.
is the type of share used in most Windows networks.
Don't export
The share will not be visible or accessible on the network.
Export read only
The share will be visible on the network (shown in My Network Places) and data can be read, but not written to the share.
Export read/write
The share will be visible on the network (shown in My Network Places) and data can be read and written to the share.
Export read only, hidden
The share will not be visible on the network (will not appear My Network Places) and data can be read, but not written to the share.
Export read/write, hidden
The share will not be visible on the network (will not appear My Network Places) and data can be read and written to the share.
Note: Setting shares to hidden is NOT a security measure, only a privacy measure.
It prevents Nosy Nellies from noticing your data, but does not protect it in any
Shares will be accessed by concatenating the server name with the share name.
A share called foo on the server Tower would be accessed at
\\Tower\foo
regardless if foo is exported as hidden or not.
unRAID is capable
however they will not be covered in this tutorial.
for more information on using NFS.
Set the following properties as appropriate for your environment.
Flash share (SMB)
Shares the UnRAID flash drive on the network as flash.
Disk shares (SMB)
Shares each disk in the array as disk1, disk2, etc.
Click the Apply button in the Export settings frame.
As previously mentioned, shares are the way UnRAID abstracts your data from the underlying file system.
When a share named foo is created, the files and folders stored in foo can be spread across multiple disks yet all be accessible at a single share point ie \\Tower\\foo.
While this is great from a usability standpoint, putting some thought into the User share settings can help avoid a few pitfalls later.
Note: For now, linking explanations to the Un-Official Manual.
This section needs a re-write!
Set the following options as appropriate for the share and click Apply.
Share name
This is the name of the share.
It must be unique to the server.
Valid characters are a-z, A-Z, 0-9, - (dash), and . (dot)
(Optional) Comments will appear in the comment field of a share in My Network Places.
Used to determine where to store data as it is copied to the share.
Min free space
The minimum free space in kilobytes that must be available on a drive for files to be copied to the drive.
This link may help in setting the correct value:
Controls at what level UnRAID will allow data to be split among multiple disks.
A list of disks preferred for use in the array.
If blank all disks are considered for use in the array.
A list of disks to which data for this share will not be copied.
Export (SMB)
Sets how the share appears on the network and how it may be accessed.
Once the share is created, there will be a new section below where you can create the next share.
Note: If parity is already enabled the bottleneck w
pick whichever method is easiest for you without considering
the speed.
There are several methods of copying files to a new array.
The simplest method is to browse to a share on the network from an existing machine and copy data across.
While this is simple it can be slow, even over a gigabit network.
If you have an available hard drive (IDE, SATA, eSATA), it is much faster to install the hard drive in the system where the files reside, copy files to this hard drive, install the hard drive in the UnRAID server, and copy the files to the array.
If you have files on an external USB hard drive, it can be mounted directly on the UnRAID server to copy files, but this will be slow due to the maximum speed of USB2 being 480Mbps.
If the files are already on an external hard drive, this is a moot point because access will be limited to USB2 speeds, therefore, it makes sense to mount the drive directly on the UnRAID server.
Note: These instructions are for copying files from a Windows system.
Step 1 Open My Computer and navigate to the location where the files to be copied to the array are stored.
Step 2 Open My Network Places and browse to the UnRAID server and share where the files are to be copied.
Step 3 Create directories if necessary.
Step 4 Select the files and/or folders in the My Computer Window then drag and drop them into the My Network Places Window.
This will begin the copy.
Step 5 Once the copy is complete, the files are now stored on the array.
Note: The NTFS driver included with the UnRAID distribution does not support
Unicode characters correctly and using this method WILL corrupt
filenames if they contain Unicode characters!
If you have any files
containing Unicode characters, it is recommended that you copy those
files across the network.
Step 1 Copy files from an existing system to an internal or external hard drive.
Step 2 Install the hard drive in the UnRAID server, power on the system, log into the web GUI and spin up the drives. Then run telnet and log in as root.
For external hard drives it is safe to just plug them into the USB or eSATA port.
It is recommended to log into the console or via a screen session if using telnet.
Step 3 Create a directory to mount the filesystem.
At the prompt type
mkdir /mnt/imported_files
Step 4 Determine the drive and partition mappings:
For NTFS file systems type
fdisk -l|grep NTFS
For FAT or FAT32 file systems type
fdisk -l|grep FAT
The result will be similar to
W95 FAT32 (LBA)
This shows 2 NTFS file systems: one at /dev/sdc1 and another at /dev/sdd1; and 1 FAT32 file system at /dev/sdh1.
Note the mapping of the file system where the files reside.
Step 5 Mount the file system in the mount point created in Step 3:
For NTFS file systems type
mount -r -t ntfs /dev/sdX /mnt/imported_files
where /dev/sdX is the device mapping from Step 4.
For FAT or FAT32 file systems type
mount -r -t vfat /dev/sdX /mnt/imported_files
where /dev/sdX is the device mapping from Step 4.
Step 6 To copy files using Midnight Commander, at the prompt type
Note: If you are comfortable navigating the filesystem and using the cp
or rsync command that is an acceptable alternative to Midnight
Commander.
Step 7 Use the arrow keys to move the highlighted bar to
in the left column and press enter to navigate up one level in the file system.
Step 8 Use the arrow keys to navigate to the
directory in the left column and press enter to open it.
Step 9 Use the arrow keys to navigate to the
/imported_files
directory and press enter to open it.
Step 10 Continue using the arrow keys and enter to navigate to the set of files you wish to copy to the array in the left column.
Step 11 Press tab to move to the right column, then use the arrow keys and enter to navigate to
/mnt/user/
directory.
You will probably need to start by going up one level in the file system like in Step 7.
Step 12 This is where the user shares are mounted in the file system.
Navigate into the share where the files from the left column will be copied.
To create a directory (folder) press F7, type the name of the new directory, and press enter.
Step 13 When you have the source files for the copy in the left column and the destination in the right column press tab to move the nav bar back to the left column.
Step 14 For each file or directory to be copied, highlight it using the up and down arrow keys then press
to select it.
Selected files and directories will turn yellow.
They can also be de-selected by pressing CTRL-T again.
Step 15 Once the files and/or directories to be copied have been selected, press F5 to initiate the copy.
Step 16 Leave everything as is in the box that appears and press Enter to copy the files.
Step 17 Once the first copy is finished you can use the preceding steps to navigate the file system and copy all the files from the disk to the array.
Step 18 When finished copying files, press F10 to exit Midnight Commander.
Then press Enter in the Are you sure box.
Step 19 After exiting Midnight Commander type
to return to the /root directory then unmount the hard drive by typing
umount /mnt/imported_files
It is now safe to power down the system and remove the hard drive, or you can preclear it and add it to your array!
Note: User level security is only available on UnRAID Pro and Plus
This section shows how to configure user level security for shares on the array.
If you are comfortable with anyone that is attached to your network - depending on your network topology this may include anyone on your wireless network! - having access to your shares as they are presently configured then user level security is not necessary.
Step 1 Connect to the
and stop the array.
Step 2 Click on Settings.
Step 3 Set Share security to User Level.
Step 4 Click Apply.
Step 5 Start the array.
Step 1 Connect to the
and click Users.
Step 2 Below root, there will now be a set of boxes in which you can assign a new user with password to the system.
Enter a username in the User name box.
Valid characters are a-z, 0-9, - (dash), _ (underscore), and . (dot). Do not use any uppercase letters.
You may also leave the password blank.
This is use they can be allowed read only access to some shares, no access to others, and denied write access to the entire array.
Note: If the username and password match the user's Windows username and
password, they will not be prompted for a password when they connect
to a share.
Step 3 Enter a password in the Password and Retype password boxes, then press apply.
Step 4 Click Shares to assign share permissions.
for more information including removing users and changing passwords.
The applicable settings for share security are Exceptions, Valid users, and Invalid Users.
This information is also available in the
Exceptions
This is a comma separated list of users that get the "opposite" of the Export (SMB) setting.
If Export is set to read-only, users in the Exceptions list get read/write access.
If Export is set to read/write, users in the Exceptions list get read only access.
Valid users
Comma separated list of users that are granted access to the share as specified by the Export (SMB) setting.
If left blank, all users not in the Invalid users are granted access.
Invalid users
Comma separated list of users that denied access to the share.
If left blank, all users not listed in Valid users are denied access.
Suppose we have a system named Tower with the following shares
and the following users
We want guests and kids to be able to watch movies but not be able to add or delete them.
Mom and dad should have full access to the Movies share so they can add new movies and delete old ones.
Export (SMB)
= read only
Exceptions
Valid users
Invalid users =
For Finances, guests and kids should not have any access and because Mom handles the finances dad should only get read access.
Export (SMB)
= read only
Exceptions
Valid users
Invalid users = kids,guest
unRAID is by no means a secure operating system and should NOT be connected directly to the Internet under any circumstances.
There are, however, a few things that can be done to provide additional security to your unRAID server.
What you choose to implement should be based on your environment, users that are granted access, and users who could potentially take access of your server.
In a Linux system root is the super user.
root can see everything, change everything, and even delete everything.
By default unRAID leaves the root password blank.
This has the benefit of making configuration an easy task but it also makes the system easier to compromise.
Without a root password, whenever you navigate to the
you are not prompted for a password.
This means that ANYONE that has access to your network can simply log in and take control of your unRAID server.
To set a root password:
Step 1 Log into the .
Step 2 Click Users.
Step 3 Enter the new password in the Password and Retype password boxes for root and click apply.
Be sure to grant just enough access to user shares.
It's easy to just give everyone read/write access to everything, but that can lead to friends or family accidentally deleting or overwriting files.
Parity can protect you from a hard drive failure, but it can't protect you from your friends and family.
The trouble is quantifying what is just enough and that is a question that only you can answer.
Think through your usage scenarios, and be stingy with permissions!
It is convenient to be able to drag and drop files to the flash drive, but setting the flash share export to disabled in
makes it harder for someone to hijack your server by modifying the startup sequence.
Do not allow ANY external access to your unRAID server that is not required.
Definitely do not allow external conso it is an insecure protocol.
If you simply MUST allow external console access set up ssh through the package manager in
and be sure to use STRONG passwords or set up a .
A VPN is more secure and can add the benefit of allowing external access to your shared files.
Directly exposing an SMB or NFS mount to the Internet is bad practice and can quickly lead to someone stealing your data or using your storage to store their files!
Allowing external access to your shared files can be done via ftp, sftp, or VPN.
Search the wiki and/or forums for more information.
Congratulations, you now have a working UnRAID server!
If you have not yet added a
to your array you should do so now to protect your data.
At this point it is recommended that you
for your UnRAID server if you have not done so already.
This will add a layer of security to your server and prevent anyone from logging into the web interface and nosing around or worse.
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This page was last modified on 25 March 2015, at 22:27.
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