Read Unraid disk in Ubuntu

[Bitbass]

I’ve been looking all over and can’t find details of this. So, please be kind and show me how bad my search-fu is.

 

Pulled a drive out of Unraid and I’m trying to read it in Ubuntu, while preserving the data. Ubuntu sees the drive but it’s tagged as “linux_raid_member” and I’m unable to mount the XFS partition. I’ve seen references to removing the MD tag using mdadm but I can’t sort out how to make that work.

 

Bottom line, I want to read a XFS drive out of Unraid in an Ubuntu system.

 

Try not to flame me too hard, I really did search for this.

[JonathanM]

Does it mount ok in Unassigned Devices in Unraid?

 

Something is strange with your setup, Unraid doesn't use mdadm at all, and to my knowledge a valid XFS drive in Unraid would never be set up as anything other than a single normal partition across the whole drive. A valid drive in Unraid should mount with no issues in any linux that supports modern XFS.

[Bitbass]

Other way around, I want to mount an Unraid XFS formatted drive in Ubuntu and I'm not able to.

[JonathanM]

1 hour ago, Bitbass said:

Other way around, I want to mount an Unraid XFS formatted drive in Ubuntu and I'm not able to.

I understand that, but if it mounts ok in Unraid using Unassigned devices, you could look in the syslog and use the mount options that worked there.

[Bitbass]

I already have it out of the Unraid system and in the Ubuntu system. I could move things around, but that's multiple reboots I'd like to avoid.

 

Guess I thought there would be an easy way to do this.

[JonathanM]

You could set up a temporary trial install of Unraid to boot the Ubuntu machine and see if it mounts.

[Bitbass]

I have the Unraid instance, just trying to avoid all of the shutdowns and shuffling that will go along with it

[trurl]

12 hours ago, Bitbass said:

Pulled a drive out of Unraid and I’m trying to read it in Ubuntu, while preserving the data.

Unless you mount it read-only, you will invalidate Unraid parity

[Bitbass]

8 hours ago, trurl said:

Unless you mount it read-only, you will invalidate Unraid parity

I'm not concerned about that. If, for some reason, I had Unraid drives but no Unraid server available to me, how do I read the drives?

 

I appreciate that you guys are giving me workarounds to my situation, but it's not really answering my question. How can I read an Unraid XFS formatted drive in an Ubuntu system when it's marked as "linux_raid_member"?

[trurl]

Was this a drive from the Unraid parity array, or from a pool?

[Bitbass]

It's a data drive from a no-parity Unraid system.

[trurl]

Is it an array drive or a pool drive?

[Bitbass]

34 minutes ago, trurl said:

Is it an array drive or a pool drive?

Sorry, I guess I'm missing what you're asking. It came out of the array in Unraid, which has no parity. I guess an array drive? I'm treating Unraid like a JBOD, but the drives are all assigned in Unraid.

[trurl]

7 minutes ago, Bitbass said:

missing what you're asking

There is the array, which can be (optionally) protected by parity, and there are pools. The default (and only pool until 6.9) is cache. You can have multiple pools, and each pool can have multiple disks if they are btrfs instead of XFS, so that is what I was wondering about.

 

7 minutes ago, Bitbass said:

treating Unraid like a JBOD

Your use of the term JBOD makes me wonder. What controller was the drive attached to in Unraid? Are you using RAID controllers?

[Bitbass]

2 minutes ago, trurl said:

There is the array, which can be (optionally) protected by parity, and there are pools. The default (and only pool until 6.9) is cache. You can have multiple pools, and each pool can have multiple disks if they are btrfs instead of XFS, so that is what I was wondering about.

 

Your use of the term JBOD makes me wonder. What controller was the drive attached to in Unraid? Are you using RAID controllers?

That drive would have been attached through an HBA. I think it's a 9207, but I could be wrong. No RAID enabled on that. Unraid definitely sees the drives as individuals.

 

Unrelated, so I hope I'm not going to confuse things. I also have a Dell R710 with a H700(?) and I have to explicitly create RAID0's for each drive if I want to pass those through without RAID being applied. That's not the case with this instance of Unraid. Just giving you some context for my familiarity with these. 

[JonathanM]

1 hour ago, Bitbass said:

I appreciate that you guys are giving me workarounds to my situation, but it's not really answering my question. How can I read an Unraid XFS formatted drive in an Ubuntu system when it's marked as "linux_raid_member"?

And you are not hearing what we are telling you, normally Unraid XFS drives do NOT show as linux raid member, implying there is something wrong. I was trying to determine whether the drive currently mounts correctly in Unraid. Given what you are telling us, I don't think it will.

 

20 hours ago, JonathanM said:

Something is strange with your setup, Unraid doesn't use mdadm at all, and to my knowledge a valid XFS drive in Unraid would never be set up as anything other than a single normal partition across the whole drive. A valid drive in Unraid should mount with no issues in any linux that supports modern XFS.

 

[JorgeB]

23 hours ago, Bitbass said:

“linux_raid_member”

This suggest the drive was previously used with Linux RAID and not properly wiped before using it with Unraid, it should still mount with Unraid, in the array or pool.

[JonathanM]

35 minutes ago, JorgeB said:

This suggest the drive was previously used with Linux RAID and not properly wiped before using it with Unraid

If that is indeed the case, is there a way to reset the partition layout to one that can be mounted in a general purpose linux without erasing the existing format and data?

[JorgeB]

3 minutes ago, JonathanM said:

If that is indeed the case, is there a way to reset the partition layout to one that can be mounted in a general purpose linux without erasing the existing format and data?

Possibly, using wipefs to delete just that info, but it's something I've never tried, so cannot help with.

[Bitbass]

It's quite possible it was in a RAID previously. That would have been some time ago. This was the piece I was missing from my understanding. I wasn't aware that "linux_raid_member" wasn't put there by Unraid. 

 

Sorry for the confusion. I'll explore wipefs. Thanks!

[JonathanM]

1 minute ago, Bitbass said:

I wasn't aware that "linux_raid_member" wasn't put there by Unraid. 

 

That's what I was trying to tell you, sorry I wasn't more explicit in how I tried to explain it.

21 hours ago, JonathanM said:

Something is strange with your setup, Unraid doesn't use mdadm at all,

 

[Bitbass]

In case someone else stumbles across this (including me) here's what I did. And it worked fine this time, but who knows if each situation will be a little different. I imagine the first command has the potential to destroy things, so use caution:

 

sudo wipefs /dev/sdf
sudo wipefs -o 0x1000 -f /dev/sdf
sudo fdisk -l
sudo xfs_repair /dev/sdf1
sudo mount /dev/sdf1 /mnt/sdf

 

I also modified fstab because of the partition being in there. It might end up being a problem for me later, but I know where to go then.  

 

Thanks for getting me headed in the right direction, even if I had trouble seeing it!