Hi I have a Raid 1 disk which I would like to access in a newly installed system to retrieve (obvious ) data.
What is the trick to mount the ssd ???
Thank and happy new year !
@ozotto just use the mount command should suffice, if you run lsblk what does it show?
localhost:/ # lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 20.5G 0 part
│ └─md1 9:1 0 20.5G 0 raid1
└─sda2 8:2 0 911G 0 part
└─md127 9:127 0 911G 0 raid1
sdb 8:16 0 447.1G 0 disk
└─sdb1 8:17 0 447.1G 0 part
└─md0 9:0 0 447.1G 0 raid1 /home/hase/RAID
sdc 8:32 0 447.1G 0 disk
└─sdc1 8:33 0 447.1G 0 part
sr0 11:0 1 1024M 0 rom
nvme0n1 259:0 0 232.9G 0 disk
├─nvme0n1p1 259:1 0 8M 0 part
├─nvme0n1p2 259:2 0 2G 0 part [SWAP]
├─nvme0n1p3 259:3 0 10G 0 part
├─nvme0n1p4 259:4 0 40G 0 part
├─nvme0n1p5 259:5 0 80G 0 part /home/hase/help
├─nvme0n1p6 259:6 0 512M 0 part /boot/efi
└─nvme0n1p7 259:7 0 100.4G 0 part /var
/usr/local
/tmp
/home
/srv
/root
/opt
/boot/grub2/x86_64-efi
/boot/grub2/i386-pc
/.snapshots
/
localhost:/ #
@ozotto Which one of those three incomplete raid setups is it?
@malcolmlewis … sorry , I should have been specific !
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 20.5G 0 part
│ └─md1 9:1 0 20.5G 0 raid1
└─sda2 8:2 0 911G 0 part
└─md127 9:127 0 911G 0 raid1
The ssd disk sda2=>md127 is connected to the system via usb.
regards
I must admit I don’t know what I have done … it is a mess.
Anyway, I had the raid disk in question connected via SATA and thought I could mount like
=> mount /dev/sda2 /home/directory-name
that did not work because, so I suspect, the type “Raid” can not be mounted.
I assum that md devices are the RAID ones where the file system is on. Not the sd ones.
But lsblk -f will show if there are file systems, and where and of what type.
@ozotto what does mdadm --examine /dev/sda show?
Thend should be able to run for example mdadm --assemble /dev/md1 /dev/sda1 dev/sdX --run
Overview
localhost:/ # lsblk -f
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
sda
└─sda1 linux_raid_member 1.0 any:0 1e0f310b-f0a5-6940-2760-29f4f0baf809
sdb
└─sdb1 linux_raid_member 1.0 any:0 1e0f310b-f0a5-6940-2760-29f4f0baf809
└─md0 xfs 08e7b793-be27-48f4-9162-8c2b5f153d6f 122.4G 73% /home/hase/RAID
sdc
├─sdc1 linux_raid_member 1.0 any:1 47e534d9-ddd4-85c3-f849-4b5f8c588a4c
│ └─md1
└─sdc2 linux_raid_member 1.0 any:0 fa4b731d-a95f-63aa-8a3b-b5439f1f725a
└─md127
sr0
nvme0n1
├─nvme0n1p1
├─nvme0n1p2 swap 1 85201cbc-681e-4276-b5bc-09ef0835de3a [SWAP]
├─nvme0n1p3 swap 1 2c9ef43e-8624-4b0c-b19c-7fb5618907b9
├─nvme0n1p4 btrfs be2572e5-0f89-4ea0-83ea-eb2775d07766
├─nvme0n1p5 xfs a5f36def-f33e-4d9b-a55e-d4f5d333e5c3 57.6G 28% /home/hase/help
├─nvme0n1p6 vfat FAT32 18E0-321B 505.1M 1% /boot/efi
└─nvme0n1p7 btrfs 8699890b-cc02-4526-8439-1a2637563ffd 64.1G 35% /var
/usr/local
/tmp
/srv
/root
/opt
/home
/boot/grub2/x86_64-efi
/boot/grub2/i386-pc
/.snapshots
/
localhost:/ #
localhost:/ # mdadm --examine /dev/sdc
/dev/sdc:
MBR Magic : aa55
Partition[0] : 1953525167 sectors at 1 (type ee)
localhost:/ #
localhost:/ # mdadm --assemble /dev/md/0_0 /dev/sdc dev/sdX --run
mdadm: Cannot assemble mbr metadata on /dev/sdc
mdadm: /dev/sdc has no superblock - assembly aborted
localhost:/ #
I suspect that we can not retrieve the file-system.
I did not reformat the disk ! So the data should be there. There are only a few files I would like to rescue (*flac and some pdf) . For that ? …how can I scan the disk and retrieve the files?
what are your thoughts ?
@ozotto Not is all lost, what about cat /proc/mdstat and mdadm --assemble --readonly /dev/md1 /dev/sdc1 --run and don’t change this…
localhost:/ # cat /proc/mdstat
Personalities : [raid1]
md127 : active raid1 sdc2[1]
955287040 blocks super 1.0 [2/1] [_U]
bitmap: 7/8 pages [28KB], 65536KB chunk
md1 : active (auto-read-only) raid1 sdc1[1]
21474176 blocks super 1.0 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md0 : active raid1 sdb1[1]
468859712 blocks super 1.0 [2/1] [_U]
bitmap: 4/4 pages [16KB], 65536KB chunk
unused devices: <none>
localhost:/ # mdadm --assemble --readonly /dev/md1 /dev/sdc1 --run
mdadm: /dev/sdc1 is busy - skipping
localhost:/ #
alternative
localhost:/ # mdadm --assemble --readonly /dev/md/0_0 /dev/sdc2 --run
mdadm: /dev/sdc2 is busy - skipping
localhost:/ #
@ozotto So if you run mdadm --stop /dev/md1 then mdadm --assemble --readonly /dev/md1 /dev/sdc1 --run then cat /proc/mdstat If it shows md1 as active, should be able to mount mount /dev/md1 /mnt
localhost:/ #
localhost:/ # mdadm --stop /dev/md1
mdadm: stopped /dev/md1
localhost:/ #
localhost:/ # mdadm --assemble --readonly /dev/md1 /dev/sdc1 --run
mdadm: /dev/md1 has been started with 1 drive (out of 2).
localhost:/ #
localhost:/ # cat /proc/mdstat
Personalities : [raid1]
md1 : active (read-only) raid1 sdc1[1]
21474176 blocks super 1.0 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk
md127 : active raid1 sdc2[1]
955287040 blocks super 1.0 [2/1] [_U]
bitmap: 7/8 pages [28KB], 65536KB chunk
md0 : active raid1 sdb1[1]
468859712 blocks super 1.0 [2/1] [_U]
bitmap: 4/4 pages [16KB], 65536KB chunk
unused devices: <none>
localhost:/ #
localhost:/ # mount /dev/md1 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/md1, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
I found the following command … maybe helpful
localhost:/ # mdadm -D /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Sun Mar 17 14:18:03 2019
Raid Level : raid1
Array Size : 468859712 (447.14 GiB 480.11 GB)
Used Dev Size : 468859712 (447.14 GiB 480.11 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Fri Jan 2 10:59:48 2026
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : any:0
UUID : 1e0f310b:f0a56940:276029f4:f0baf809
Events : 10410
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 17 1 active sync /dev/sdb1
localhost:/ #
localhost:/ # mdadm -D /dev/md/0_0
/dev/md/0_0:
Version : 1.0
Creation Time : Thu Jan 1 11:20:12 2026
Raid Level : raid1
Array Size : 955287040 (911.03 GiB 978.21 GB)
Used Dev Size : 955287040 (911.03 GiB 978.21 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Thu Jan 1 18:08:37 2026
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : any:0
UUID : fa4b731d:a95f63aa:8a3bb543:9f1f725a
Events : 1413
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 34 1 active sync /dev/sdc2
localhost:/ #
localhost:/ # mdadm -D /dev/md1
/dev/md1:
Version : 1.0
Creation Time : Thu Jan 1 13:05:10 2026
Raid Level : raid1
Array Size : 21474176 (20.48 GiB 21.99 GB)
Used Dev Size : 21474176 (20.48 GiB 21.99 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Fri Jan 2 11:01:28 2026
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : any:1
UUID : 47e534d9:ddd485c3:f8494b5f:8c588a4c
Events : 41
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 33 1 active sync /dev/sdc1
localhost:/ #
and I tried …
localhost:/ # mount /dev/md/0_0 /home/hase/ext-ssd
mount: /home/hase/ext-ssd: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
@ozotto mdadm -D /dev/md1 shows sdc1 as active and degraded, so mount /dev/md1 /mnt or if it’s sdc2 you want then use the process for that one after stopping.
ok … I stopped md1 and md/0_0
I tried to mount md/0_0 …since I am trying to access sdc2
localhost:/ # mount /dev/md/0_0 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
as you suggested further up I …
localhost:/ # mdadm --assemble --readonly /dev/md/0_0 /dev/sdc2 --run
mdadm: /dev/md/0_0 has been started with 1 drive (out of 2).
localhost:/ #
then I tried to mount
localhost:/ # mount /dev/md/0_0 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
localhost:/ # mount /dev/md/0_0 /home/hase/ext-ssd
mount: /home/hase/ext-ssd: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
the following seamed to be the problem
wrong fs type, bad option, bad superblock on /dev/md127, missing codepage
I guess (!?) for the partition must be some sort of “header”-file. Is it possible to edit this file ?
You have to stop things first, then use /dev/md127 and /mnt don’t use anything but for the moment…
OK !
…stopped /dev/md/0_0 and /dev/md1 (md1 was not running)
localhost:/ # mount /dev/md127 /mnt
mount: /mnt: special device /dev/md127 does not exist.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
localhost:/ #
@ozotto you have to start it as well… look at the steps…
- check cat /proc/mdstat
- stop as required (I would stop everything)
- assemble for the one device only
- check mdstat output again to ensure only the one you want is running
- mdadm -D /dev/mdXXX
- then mount…
…stopped md1 and md/0_0 (can not stop md0 => would the test system)
then…
localhost:/ # mdadm --assemble --readonly /dev/md/0_0 /dev/sdc2 --run
mdadm: /dev/md/0_0 has been started with 1 drive (out of 2).
localhost:/ #
localhost:/ # cat /proc/mdstat
Personalities : [raid1]
md127 : active (read-only) raid1 sdc2[1]
955287040 blocks super 1.0 [2/1] [_U]
bitmap: 7/8 pages [28KB], 65536KB chunk
md0 : active raid1 sdb1[1]
468859712 blocks super 1.0 [2/1] [_U]
bitmap: 4/4 pages [16KB], 65536KB chunk
unused devices: <none>
localhost:/ #
localhost:/ # mdadm -D /dev/md/0_0
/dev/md/0_0:
Version : 1.0
Creation Time : Thu Jan 1 11:20:12 2026
Raid Level : raid1
Array Size : 955287040 (911.03 GiB 978.21 GB)
Used Dev Size : 955287040 (911.03 GiB 978.21 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Thu Jan 1 18:08:37 2026
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Consistency Policy : bitmap
Name : any:0
UUID : fa4b731d:a95f63aa:8a3bb543:9f1f725a
Events : 1413
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 34 1 active sync /dev/sdc2
localhost:/ #
localhost:/ # mount /dev/md/0_0 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/md127, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
localhost:/ #
@ozotto but /dev/md127 is the device, your fixated on this /dev/md_0_0 device all the time? Check each command output after stopping devices…
Since your not showing ALL information, it’s hard to surmize, small steps are needed…