Dev1 Galaxy Forum / [SOLVED] Mounting HDD in a USB cradle

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stevend) — Mon, 13 Jan 2025 22:01:02 +0000

TL;DR: you guys are fantastic! It's working now, thanks for the help.

rolfie wrote:

Yes, LVM is an additional layer. But as it looks like you have not really seen any issues for many years with it, so what?

I have no problem with LVM for those who need it or gain some advantage from it, and I'm not saying that it is "bad". I'm fully aware that the sys admins I used to work with love it for good reason. But in five years I never once needed any of its features, but I'm now paying the cost of that extra complexity. That's all I'm saying.

Moving along, I have made a copy of the HDD, changed the Array UUID so I can use the copy rather than the original, and got to this point:

root@sharon:~# /sbin/mdadm --assemble --run /dev/md1 --update=uuid --uuid=c4ca5085:e2e52c3d:0527066c:5e438460 /dev/sda1
mdadm: /dev/md1 has been started with 1 drive (out of 2).

root@sharon:~# vgchange -a y
  3 logical volume(s) in volume group "fedora" now active

root@sharon:~# vgscan
  Found volume group "fedora" using metadata type lvm2

root@sharon:~# mount /dev/mapper/fedora-home /mnt

And now I can access the files! Thank you all again for your help!

(Dances the Dance Of Joy.)

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stargate-sg1-cheyenne-mtn) — Mon, 13 Jan 2025 08:07:34 +0000

mostly for the convenience of future thread visitors, since DD was mentioned:

https://en.wikipedia.org/wiki/Ddrescue

also please visit the other projects as well for additional food for thought:

https://en.wikipedia.org/wiki/Ddrescue#Unrelated_recovery_tools

sometimes i remember to remember to marvel at each and every successful storage media activation(but oh how the expletives flow when they don't...sigh)

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (rolfie) — Sun, 12 Jan 2025 14:17:45 +0000

Yes, LVM is an additional layer. But as it looks like you have not really seen any issues for many years with it, so what? Ok it has its own terms you need to get used to like physical volume, volume group, logical volume, etc. Can be learned, there is a LVM HowTo in the internet. Just look for it. BTW: I am using LVM for many many years by now, no real issues with it.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stevend) — Sun, 12 Jan 2025 13:15:55 +0000

rolfie wrote:

vgchange -a y will do the job. Quote the output here please.

Thanks, will do.

I'm now working in an area well out of my comfort zone, so before I do that I'm making an exact copy of the drive using dd in case of accidents. (I know, I should have done this earlier, mea culpa. But better late than never.) Looks like it will take another 15 hours.

I should be able to get back to this about this time tomorrow.

stargate-sg1-cheyenne-mtn wrote:

why no mention of important information like "raid array" and "managed by lvm" in the original post?

Fair question.

Because I had set that drive up years ago and had completely forgotten how it was configured until I started seeing the output of commands. I had completely forgotten about using LVM using I saw the error message unknown filesystem type 'LVM2_member'. It was just a check box in an installer something like five years ago, and then never thought about since. (Until now.)

Don't let my ability to run lsblk on the command line fool you, I am very much a novice who knows just enough to get into trouble but not enough to get out of it again without help

(If I had known LVM is so ... complicated ... I would never have used it in the first place, but I used to work with a rockstar techie who told me "Always use LVM because it is totally awesome.")

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stargate-sg1-cheyenne-mtn) — Sun, 12 Jan 2025 06:29:03 +0000

shouldn't the thread title be less misleading? how about "Can I recover data from a raid member?" also, why no mention of important information like "raid array" and "managed by lvm" in the original post?

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (rolfie) — Sat, 11 Jan 2025 21:13:28 +0000

vgchange -a y will do the job. Quote the output here please.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (ralph.ronnquist) — Sat, 11 Jan 2025 21:06:11 +0000

I think you need to "activate the volume group" first; doing so will set up the dm objects for the lvms, and the /dev/mapper (symbolic) links for them, to let you mount them "by name". I believe it'd be something like:

(bogus advice removed)

EDIT: check the man pages; I don't use lvm regularly (being happy enough without that confusion layer) so may well be wrong on the detail.
EDIT2: I blanked my bogus advice --- see @rolfie's post.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (greenjeans) — Sat, 11 Jan 2025 18:11:35 +0000

Just a question as i'm not familiar with that stuff either, but your command mount /dev/mapper/fedora-home /mnt

Shouldn't that be mount /dev/fedora/home /mnt ?

Possibly some useful info : https://askubuntu.com/questions/217571/ … om-gparted

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (PedroReina) — Sat, 11 Jan 2025 17:48:08 +0000

LVM is out of my knowledge. Maybe this link could help:
https://superuser.com/questions/116617/ … lvm-volume

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (RedGreen925) — Sat, 11 Jan 2025 17:30:51 +0000

So now I'm stuck again.

And I would think you will be until you have all drives in the array available to re-assemble and mount it. Try it doing that I think you will get much farther along on your recovery efforts.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stevend) — Sat, 11 Jan 2025 16:38:37 +0000

RedGreen925 wrote:

It seems to think it is a member of a raid array, is/was it?

Yes. Furthermore, it was managed by LVM.

Brave search suggests an AI-generated answer that I don't trust but I've used it as a guide to explore further:

https://search.brave.com/search?q=unkno … 56039f2451

I've gone ahead and installed lvm and got this far:

root@sharon:/home/steve# /sbin/lvdisplay
  --- Logical volume ---
  LV Path                /dev/fedora/root
  LV Name                root
  VG Name                fedora
  LV UUID                GDRkyj-RUSf-92N9-lhMX-Kld6-656Y-A66U61
  LV Write Access        read/write
  LV Creation host, time localhost, 2021-10-05 01:43:11 +1100
  LV Status              NOT available
  LV Size                50.00 GiB
  Current LE             12800
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
   
  --- Logical volume ---
  LV Path                /dev/fedora/home
  LV Name                home
  VG Name                fedora
  LV UUID                zwag1C-ZZnW-Pmm8-wjae-EZPM-80E7-ko2M3w
  LV Write Access        read/write
  LV Creation host, time localhost, 2021-10-05 01:43:17 +1100
  LV Status              NOT available
  LV Size                164.41 GiB
  Current LE             42090
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
   
  --- Logical volume ---
  LV Path                /dev/fedora/swap
  LV Name                swap
  VG Name                fedora
  LV UUID                NGBkoh-d12e-JsFz-Gl4V-hHYO-spE2-9RGGup
  LV Write Access        read/write
  LV Creation host, time localhost, 2021-10-05 01:43:34 +1100
  LV Status              NOT available
  LV Size                7.83 GiB
  Current LE             2005
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

I only care about the "/dev/fedora/home" volume.

root@sharon:/home/steve# /sbin/vgs
  VG     #PV #LV #SN Attr   VSize    VFree
  fedora   1   3   0 wz--n- <222.25g    0 

root@sharon:/home/steve# /sbin/lvs
  LV   VG     Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  home fedora -wi------- 164.41g                                                    
  root fedora -wi-------  50.00g                                                    
  swap fedora -wi-------   7.83g                                                    

root@sharon:/home/steve# mount /dev/mapper/fedora-home /mnt 
mount: /mnt: special device /dev/mapper/fedora-home does not exist.
       dmesg(1) may have more information after failed mount system call.

So now I'm stuck again.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (RedGreen925) — Sat, 11 Jan 2025 15:46:15 +0000

Nothing is ever that easy

It seems to think it is a member of a raid array, is/was it? Try mount -t ext4 /dev/sdb1 /mnt to tell it the filesystem to use when mounting the device partition and the output of the fdisk -l /dev/sdb would be nice to see as well if it continues to insist it cannot mount it.

Edit: Apparently answered my raid question while posting my reply, you need all of the devices in an array present to be able to use it, I think anyways never used it in my life so cannot be certain.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stevend) — Sat, 11 Jan 2025 15:42:06 +0000

I installed the mdadm package and tried this:

root@sharon:/home/steve# /sbin/mdadm --assemble --run /dev/md0 /dev/sdb1
mdadm: /dev/md0 has been started with 1 drive (out of 2).
root@sharon:/home/steve# mount /dev/md0 /mnt
mount: /mnt: unknown filesystem type 'LVM2_member'.
       dmesg(1) may have more information after failed mount system call.

dmesg says this:

[1052642.242707] device-mapper: core: CONFIG_IMA_DISABLE_HTABLE is disabled. Duplicate IMA measurements will not be recorded in the IMA log.
[1052642.242744] device-mapper: uevent: version 1.0.3
[1052642.242823] device-mapper: ioctl: 4.47.0-ioctl (2022-07-28) initialised: dm-devel@redhat.com
[1052705.382556] md: md0 stopped.
[1052705.401450] md/raid1:md0: active with 1 out of 2 mirrors
[1052705.886437] md0: detected capacity change from 0 to 466087936

Running lsblk shows this entry (plus the usual ones seen earlier):

sdb           8:16   0   1.8T  0 disk  
└─sdb1        8:17   0 222.4G  0 part  
  └─md0       9:0    0 222.2G  0 raid1

So now I'm out of ideas.

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (stevend) — Sat, 11 Jan 2025 15:38:28 +0000

PedroReina wrote:

you can mount it typing this order as root: mount /dev/sdb1 /mnt.

Nothing is ever that easy

root@sharon:/home/steve# mount /dev/sdb1 /mnt
mount: /mnt: unknown filesystem type 'linux_raid_member'.
       dmesg(1) may have more information after failed mount system call.

I looked at dmesg and this seems to be the only relevant information:

[1051665.382026] usb 2-4: new SuperSpeed USB device number 7 using xhci_hcd
[1051665.403592] usb 2-4: New USB device found, idVendor=152d, idProduct=0578, bcdDevice= 1.00
[1051665.403612] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[1051665.403619] usb 2-4: Product: External Disk 3.0
[1051665.403624] usb 2-4: Manufacturer: JMicron
[1051665.403628] usb 2-4: SerialNumber: 784158818BA3
[1051665.409940] scsi host2: uas
[1051665.410807] scsi 2:0:0:0: Direct-Access     WDC WD20 SPZX-75UA7T0     8102 PQ: 0 ANSI: 6
[1051665.413999] sd 2:0:0:0: Attached scsi generic sg1 type 0
[1051668.840568] sd 2:0:0:0: [sdb] 3907029168 512-byte logical blocks: (2.00 TB/1.82 TiB)
[1051668.840586] sd 2:0:0:0: [sdb] 4096-byte physical blocks
[1051668.840830] sd 2:0:0:0: [sdb] Write Protect is off
[1051668.840844] sd 2:0:0:0: [sdb] Mode Sense: 53 00 00 08
[1051668.841211] sd 2:0:0:0: [sdb] Disabling FUA
[1051668.841220] sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[1051668.885980] sd 2:0:0:0: [sdb] Preferred minimum I/O size 4096 bytes
[1051668.885995] sd 2:0:0:0: [sdb] Optimal transfer size 33553920 bytes not a multiple of preferred minimum block size (4096 bytes)
[1051668.902926]  sdb: sdb1
[1051668.903172] sd 2:0:0:0: [sdb] Attached SCSI disk

Re: [SOLVED] Mounting HDD in a USB cradle

dummy@example.com (PedroReina) — Sat, 11 Jan 2025 12:33:27 +0000

Your USB-connected disk is recognized as /dev/sdb1. So, you can mount it typing this order as root: mount /dev/sdb1 /mnt. After that, you can access to its content through the /mnt/ directory. When finished, type as root umount /mnt, wait a bit for the prompt and unplug.