[HowTo] SnapRAID in OMV

In the plugin, the Diff Script Settings might interest you. After configuring them you can press the Scheduled diff button to set up an automated run of the diff/sync/scrub.

I do not use this feature myself, preferring to use one of the available third party snapRAID helper scripts.

OMV 4 - Removing a disk - I've been loosing files (Not folder it seems, just the contents) off my WD 4TB drive which is part of my snapraid setup.

To try to pin down the cause I decided to remove the drive from snapraid and run it as a single HDD without influence from any plugins.

I'd like to think I used this method, but it hasn't really worked as I 'd imagined :o(

"How can I remove a data disk from an existing array?

To remove a data disk from the array do:

• Change in the configuration file the related "disk" option to point to an empty directory - (Created /empty)
  
• Remove from the configuration file any "content" option pointing to such disk - (Deleted the line)
  
• Run a "sync" command with the "-E, --force-empty" option:
  Code

  snapraid sync -E

  The "-E" option tells at SnapRAID to proceed even when detecting an empty disk.
• When the "sync" command terminates, remove the "disk" option from the configuration file. - (Duly Deleted)
  

Your array is now without any reference to the removed disk. "

I deleted the drive in the GUI and rebooted for good measure.

Tested - snapraid check, and I got;

Disk '4tbdata01' with uuid '2f54d155-695d-48e5-a50b-d13f39f6d0e8' not present in the configuration file!

If you have removed it from the configuration file, please restore it

If you have renamed it, run 'sync' to update the new name

Diff and sync give the same response.

The configuration file looks like this after the procedure, which is what I might expect.

# this file was automatically generated from

# openmediavault Arrakis 4.1.35-1

# and 'openmediavault-snapraid' 3.7.7

block_size 256

autosave 0

#####################################################################

# OMV-Name: 4tbparity01 Drive Label: 40tbsdb

parity /srv/dev-disk-by-label-40tbsdb/snapraid.parity

#####################################################################

# OMV-Name: 2tbdata01 Drive Label: 2tbsdc

content /srv/dev-disk-by-label-2tbsdc/snapraid.content

disk 2tbdata01 /srv/dev-disk-by-label-2tbsdc

#####################################################################

# OMV-Name: 2tbdata02 Drive Label: 2tbsde

content /srv/dev-disk-by-label-2tbsde/snapraid.content

disk 2tbdata02 /srv/dev-disk-by-label-2tbsde

#####################################################################

# OMV-Name: 1tbdata01 Drive Label: 1tbsdd

content /srv/dev-disk-by-label-1tbsdd/snapraid.content

disk 1tbdata01 /srv/dev-disk-by-label-1tbsdd

exclude /snapraid.conf*

exclude *.unrecoverable

exclude lost+found/

exclude aquota.user

exclude aquota.group

exclude /tmp/

exclude .content

exclude *.bak

1 x Parity and 3 x data drives minus the previous data drive.

Where did I go wrong?

Zitat von wltdbetter

• Change in the configuration file the related "disk" option to point to an empty directory - (Created /empty)
  

For the above step, exactly what did you have for that disk in the snapraid.conf file?

Zitat von gderf

For the above step, exactly what did you have for that disk in the snapraid.conf file?

I deleted it without thinking but from memory something like this

disk 4tbdata01 /srv/dev-disk-by-label-4tbsdf

Changed to disk 4tbdata01 /srv/empty

If /srv/empty existed and was an empty directory, then snapraid sync -E should have worked and removing the disk 4tbdata01 entry in snapraid.conf should have been the end of it.

Zitat von gderf

If /srv/empty existed and was an empty directory, then snapraid sync -E should have worked and removing the disk 4tbdata01 entry in snapraid.conf should have been the end of it.

Yes. I'm puzzled. The chances are that i've been fat fingered or distracted.

I think I could probarbly re-add the drive and try the procedure again, but having gotten this far, is there another way of telling OMV that the drive is no longer part of Snapraid which would allow me to run the maintenance commands on the rest of the array?

I don't think there is any other way. The drive is probably still referenced in the snapraid.content file until it is properly removed.

I am not sure why the OMV snapRaid plugin will allow you to remove a drive from the configuration without at least suggesting that some further manual intervention is needed.

So, my 30TB NAS is ready. All data is copied from 3 other older OMV installations.

yesterday I have manually started sync and waited some many hours and it was ready this morning. Then enabled cron en started one time the job manually.

Got an email and info was sent.

in OMV5 I have enabled to SnapRaid diff .. Looking in the cron I noticed that it was starting a script in /usr/sbin/omv-snapraid-diff

what contains the diff script SCRIPTVERSION="1.1.0"

Kewl !

Zitat von aroundmyroom

So, my 30TB NAS is ready. All data is copied from 3 other older OMV installations.

yesterday I have manually started sync and waited some many hours and it was ready this morning. Then enabled cron en started one time the job manually.

Got an email and info was sent.

in OMV5 I have enabled to SnapRaid diff .. Looking in the cron I noticed that it was starting a script in /usr/sbin/omv-snapraid-diff

what contains the diff script SCRIPTVERSION="1.1.0"

Kewl !

Alles anzeigen

Although the included SnapRaid script is fine, it's very basic and there are better alternatives which cover more stuff.

Have a look at the one I'm using now, you won't find it as is because I've customized it. I run it everyday with the settings you see, but you can customize many of them. Every setting that can be customized is documented so you understand what you're changing.

You need to rename the file to sh.

EDIT FROM THE FUTURE (2022)
The script attached here was just an experiment. Please do not use it!

Take a look my GitHub repository here to download the current version of the script, which has been expanded a lot also thanks to the community!

Thanks..

auanasgheps

Would also be nice to know what crontab command you use to start this daily

as this custom script needs some additional parameters

oeps.. scripts was wrongly moved to the server causing some breaks to dissapear.

Zitat von aroundmyroom

Thanks..

auanasgheps

Would also be nice to know what crontab command you use to start this daily

as this custom script needs some additional parameters

oeps.. scripts was wrongly moved to the server causing some breaks to dissapear.

Alles anzeigen

Just create a scheduled job from the GUI that executes this script when you want. I've set it everyday at 12pm (midday), but it's my personal preference.

What do you mean was wrongly moved?

I copied it to my windows system in notepad, than copied it to my console, but here something went wrong

I solved that.

I now know what i can do

Line endings in Windows Notepad files are not the same as those in Linux text files. The two are not compatible.

Zitat von gderf

Line endings in Windows Notepad files are not the same as those in Linux text files. The two are not compatible.

That's what I was about to say! You either convert line endings with Notepad++... or just transfer the file over.

The line ending thing I learnt it at my expense some time ago...

Try Wordpad in Windows next time and see what happens.

Hi,

I am totally new to OMV and is trying to test out using it with SnapRaid. But I am having some weird trouble selecting disks.

I have 4x 1TB disks that I want to set up as 3 data drives with content file and 1 disk as parity,

Have installed the OMV-Extras and the SnapRaid plugin. The disks are empty.

When I open SnapRaid->Drives and choose to Add drives, I get a pop-up. When I select the dropdown list I get a millisecond of an updating spinning arrow and then the list is empty.

But the disks are there and they do show up if I for instance try to create a regular raid.

Really have no idea but have tried to remove SnapRaid, reboot, reinstall, reboot - but it stays the same.

Any help would be appreciated

I have attached my syslog.

You say the disks are empty but are they formatted and contain a filesystem yet?

#619: I originally tried having them as wiped and blank, and have since my post tried having them individually formatted (XFS) under Filesystems. Alas, didn't change the behavior of SnapRaid dropdown menu.

I can add that the setup is an Intel DQ77KB motherboard with 16GB RAM, 3470T CPU. OMV is installed to a Samsung 256GB miniPCIe SSD, the four disks are all 1TB Seagate 2.5" - ST1000LM035-1RK1. All the 1TB disks are set up to not power down. I want to do spindown, but I figured they might have trouble spinning up fast enough for the listing in the dialogue box to catch on. But that didn't change anything.

Have you mounted the drives yet?

Can you create directories and files on these drives? If so I have no idea what the problem is.

Zitat von gderf

Have you mounted the drives yet?

Can you create directories and files on these drives? If so I have no idea what the problem is.

I ended up rolling back everything, including OMV-Extras, rebooting and then going again. Worked this time. Probably some n00b mistake on my part. Thank you for responding to my cry for help