Rescuing data off RAID disks

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xjas

Rescuing data off RAID disks

Post by xjas »

I had a little 2-bay Raidon NAS (SL3650-LB2) running for a while with 2x2TB in RAID1. Unfortunately it seems to have died (power supply problems.) I'm fed up with messing with it so I'm going to replace it with a 4-drive FreeNAS setup like I should have built in the first place. :P

Anyway obviously I'd like to rescue the data. The Raidon box ran embedded Linux (not sure what version) and formatted its drives in XFS. Can I plug the drives into a standard desktop PC and have it recognize the RAID volume without screwing up the file system? Or can I plug just *one* drive in and will it show up as a single volume?

Any help is appreciated - kind of paranoid while messing with my backup storage. Thanks.
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
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DeMus

Re: Rescuing data off RAID disks

Post by DeMus »

xjas wrote:I had a little 2-bay Raidon NAS (SL3650-LB2) running for a while with 2x2TB in RAID1. Unfortunately it seems to have died (power supply problems.) I'm fed up with messing with it so I'm going to replace it with a 4-drive FreeNAS setup like I should have built in the first place. :P

Anyway obviously I'd like to rescue the data. The Raidon box ran embedded Linux (not sure what version) and formatted its drives in XFS. Can I plug the drives into a standard desktop PC and have it recognize the RAID volume without screwing up the file system? Or can I plug just *one* drive in and will it show up as a single volume?

Any help is appreciated - kind of paranoid while messing with my backup storage. Thanks.
Don't apologize, you should be paranoid when messing with your backup. I think, but mind you it is a guess, that you can use one disk of the RAID and connect it and be able to read it since you used RAID 1: mirror. You have the same, complete, info on both disks.
I would however be wrong so just google the problem and you will find many answers. http://superuser.com/questions/83923/ca ... to-be-read Here they say that if you have RAID 1 made with software raid (mdadm) then yes. When it is a hardware RAID made using a RAID controller then no since there is data on the disk referring to the controller.
Just read, ask around before you do something cause you never know what will happen.
Last edited by DeMus on Fri Aug 19, 2016 12:21 am, edited 1 time in total.
Laurent85
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Re: Rescuing data off RAID disks

Post by Laurent85 »

Connect both drives to your computer, from Mint open a terminal to install mdadm:

Code: Select all

apt install mdadm
Then post back the command results:

Code: Select all

sudo lsblk -o name,size,fstype,uuid,parttype,label,mountpoint
sudo mdadm --examine --scan
Image
kwisher

Re: Rescuing data off RAID disks

Post by kwisher »

I would suggest getting the new NAS setup and running first before doing ANYTHING with the 2 existing disks. Were you planning on using the existing disks in the new NAS or 4 new disks? I would highly suggest cloning the existing disks before any attempts at data rescue just in case something go awry.
Petermint
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Re: Rescuing data off RAID disks

Post by Petermint »

What happened? Were your disks using LVM or anything?

I ask because I tried to recover files from one disk of a Linux software RAID 1 array and could not access anything. I did not have a record of the configuration used to create the array. One disk died. Every attempt to recreate the array failed. Every attempt to recover files from the remaining disk failed.

I used to easily recover files from either disk created by the software RAID 1 supplied in XP server. Both disks were identical and usable outside of the array. In fact I often used that as a simple way to replicate system disks.

My attempts at Linux software RAID 1 have used a few options and in every case a recovery from a single disk has failed. Now I backup to a single disk and let rsync create the second disk.

I would like to see how you use lsblk and mdadm to recreate the array from a single disk.
xjas

Re: Rescuing data off RAID disks

Post by xjas »

Petermint wrote:What happened? Were your disks using LVM or anything?

I ask because I tried to recover files from one disk of a Linux software RAID 1 array and could not access anything. I did not have a record of the configuration used to create the array. One disk died. Every attempt to recreate the array failed. Every attempt to recover files from the remaining disk failed.

I used to easily recover files from either disk created by the software RAID 1 supplied in XP server. Both disks were identical and usable outside of the array. In fact I often used that as a simple way to replicate system disks.

My attempts at Linux software RAID 1 have used a few options and in every case a recovery from a single disk has failed. Now I backup to a single disk and let rsync create the second disk.

I would like to see how you use lsblk and mdadm to recreate the array from a single disk.
Man, sorry I forgot to reply to this, but in case it's still relevant months later:

I ended up plugging in both drives into an external SATA bay and they showed up as a RAID array using XFS, so I was able to get all the data off them without any drama. (The machine I mounted them on already has a RAID1 volume running so mdadm etc. was already set up.) I don't know if they were using LVM; I've still got both disks as they were so I can look further into how they were configured when I have some time.
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