How to retrieve data on HDs from dead NAS?

RAID, Volume, storage pool, hard drive, USB, SSD cache and iSCSI LUN
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Neut
Posts: 11
Joined: 22 Jan 2023, 21:15

Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

As far as my noob self can determine,the empty drive is /dev/sda
The first of the four former NAS HDs is /dev/sdb1, /sdb2, /sdb3, /sdb4 (/sbb4 being the biggest partition, by far).
The remaining HDs are /dev/sdc1, etc. through /dev/sde4.

I tried ddrescue, but it failed after 30 hours as there was no space on the output file. Not sure what to do about that. And I could not save the mapfile.
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rapcat
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Joined: 07 Jan 2023, 01:27

Re: How to retrieve data on HDs from dead NAS?

Post by rapcat »

Neut wrote: 28 Jan 2023, 09:36 I'd added a new HD to store all 17TB of data, and created a folder on it called DATA. I tried mount /dev/vg0/lv0 /mnt /DATA, but got mount point does not exist.

I can mount the TOS_VOLUME_2021-, but none of my actual data are there, just some TerraMaster program things.

Puzzling.
Here you were going in a good direction with the information provided by the commands pvscan, vgscan and lvscan.
Create the folder "/mnt/DATA" and try again. You should be able to see your files in /mnt/DATA/ and then copy them into you new hard drive.
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Neut
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Joined: 22 Jan 2023, 21:15

Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

It seems the new HD is /dev/sda, which has the directory DATA (in theory).

However, if I open Files, I can locate neither the HD, nor the DATA folder. I do not understand how Files works (makes me long for DOS).
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rapcat
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Joined: 07 Jan 2023, 01:27

Re: How to retrieve data on HDs from dead NAS?

Post by rapcat »

Neut wrote: 02 Feb 2023, 22:50 It seems the new HD is /dev/sda, which has the directory DATA (in theory).

However, if I open Files, I can locate neither the HD, nor the DATA folder. I do not understand how Files works (makes me long for DOS).
With the command mount, we're not trying to mount the data in the new HD.. Mounting in any folder you should be able to see the data from your terramaster drive in any folder you make the mount.. Then after that you should be able to copy the data to the new hard drive. Imagine it is like a door to the files of your tnas drive.
I suggest you to read again the first message I wrote and try it to mount your files in your local drive (not the new one).
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Neut
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Joined: 22 Jan 2023, 21:15

Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

The HD with the DATA folder on it seems to be /dev/sda

I cannot locate the DATA folder in Files, though. Dunno why.
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Neut
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Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

Thanks to gparted, Ubuntu now "sees" three of the four partitions on the HDs from the NAS as cohesive units /dev/md126, /dev/md126, and /dev/md127. It looks like /dev/md126 is the big one, with all my data, but I don't want to flock it up trying to mount it incorrectly. I suspect that sudo mount /dev/md126 would to it, if possible, but safety implies . . .
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Neut
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Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

I tried to mount /dev/md126 and tried to mount /dev/vg0, but both times I get 'can find in /etc/fstab'. For pity's sake! I'm just tryna get my data back.
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Neut
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Re: How to retrieve data on HDs from dead NAS?

Post by Neut »

New Info!

As per your direction, I re-read your original post (d'oh!). I opened Files, and noticed an empty folder called 'rescue', I I tried

sudo mount /dev/vg0/lv0 /mnt/rescue and I got

mount: /mnt/rescue: special device /dev/lv0 does not exist.

Hmmm, I'll look again, with authority:

user@BOB-II:/mnt/rescue$ sudo -i
root@BOB-II:~# pvscan
WARNING: Not using device /dev/sda2 for PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc.
WARNING: PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc prefers device /dev/md127 because device name matches previous.
PV /dev/md127 VG vg0 lvm2 [17.26 TiB / 0 free]
Total: 1 [17.26 TiB] / in use: 1 [17.26 TiB] / in no VG: 0 [0 ]


Okay, it seems that vg0 should still be viable, so,

root@BOB-II:~# vgscan
WARNING: Not using device /dev/sda2 for PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc.
WARNING: PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc prefers device /dev/md127 because device name matches previous.
Found volume group "vg0" using metadata type lvm2
root@BOB-II:~# lvscan
WARNING: Not using device /dev/sda2 for PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc.
WARNING: PV M6mQBk-h0tl-5dJT-eLX4-cBJ7-VRUq-c6Slvc prefers device /dev/md127 because device name matches previous.
inactive '/dev/vg0/lv0' [17.26 TiB] inherit


It appears /dev/vg0/lv0 exists, but this seems a bit iffy. I looked at Disks to see the mount info, and I find '19 TB RAID Array' is device /dev/md/UTOSUSER-X86-S64, so I try to mount that:

root@BOB-II:~# sudo mount /dev/md/UTOSUSER-X86-S64
mount: /dev/md/UTOSUSER-X86-S64: can't find in /etc/fstab.


Dang. Okay, maybe I can mount /dev/vg0/lv0 now.

root@BOB-II:~# MOUNT /DEV/VG0/LV0 /MNT/RESCUE
MOUNT: command not found


Oops.

root@BOB-II:~# mount /dev/vg0/lv0 /mnt/rescue
mount: /mnt/rescue: special device /dev/vg0/lv0 does not exist.


Dangit. Do as you're told.

root@BOB-II:~# sudo mkdir /mnt/disk
root@BOB-II:~# mount /dev/vg0/lv0 /mnt/disk
mount: /mnt/disk: special device /dev/vg0/lv0 does not exist.
root@BOB-II:~# mount /dev/vg0/lv0 /mnt/disk
mount: /mnt/disk: special device /dev/vg0/lv0 does not exist.


I look at Gparted and see that the 17.26TiB block has the right vg and lv, and the member /dev/md127, and the partition path is /dev/md127. So I figure I'll try to mount that:
mount /dev/md127 /mnt/disk
mount: /mnt/disk: unknown file system type 'LVM2_member'.


not again.

sudo apt install lvm2

lvm2 is already the latest version
Gosh, thanks (I've installed lvm2 about four times already).

Trying to mount /dev/md127 always results in unknown filesystem type, and trying to mount /dev/vg0/lv0 always results in /dev/vg0/lv0 dos not exist.

I'm baffled. Again.
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