CodeLoft: 2021

choose the commands you need ;-)

I was able to recover files from a single Raid 1 disk from a QNAP TS-253A with RHEL 8.5

Look out for disks

sudo lshw -class disk -short

H/W path Device Class Description
======================================================
/0/100/1f.2/1 /dev/sdb disk 4TB WDC WD40EFRX-68N

Partitions...

sudo cat /proc/partitions | grep sdb

major minor #blocks name
   8       16 3907018584 sdb
   8       17     530125 sdb1
   8       18     530142 sdb2
   8       19 3897063763 sdb3
   8       20     530144 sdb4
   8       21    8353796 sdb5

the biggest one is the one ;-)

sudo mdadm --examine /dev/sdb3

/dev/sdb3:
          Magic : a92b4efc
        Version : 1.0
    Feature Map : 0x0
     Array UUID : db8544d5:f3913fc6:b6f8d0e0:7265ecf1
           Name : 2
Creation Time : Sat Dec 30 02:12:17 2017
     Raid Level : raid1
   Raid Devices : 2

Avail Dev Size : 7794127240 sectors (3.63 TiB 3.99 TB)
     Array Size : 3897063616 KiB (3.63 TiB 3.99 TB)
Used Dev Size : 7794127232 sectors (3.63 TiB 3.99 TB)
   Super Offset : 7794127504 sectors
   Unused Space : before=0 sectors, after=264 sectors
          State : clean
    Device UUID : c3fc65bb:e3086e6d:3beed8ef:a8b8f437

    Update Time : Fri Nov 26 09:44:05 2021
Bad Block Log : 512 entries available at offset -8 sectors
       Checksum : 95b36245 - correct
         Events : 60271

   Device Role : Active device 0
   Array State : A. ('A' == active, '.' == missing, 'R' == replacing)

list Raid-Configs with mdadm

sudo mdadm --detail /dev/md*

-> lists raid-configs. only the one I wanted is printed here:

/dev/md125:
           Version : 1.0
     Creation Time : Sat Dec 30 02:12:17 2017
        Raid Level : raid1
        Array Size : 3897063616 (3.63 TiB 3.99 TB)
     Used Dev Size : 3897063616 (3.63 TiB 3.99 TB)
      Raid Devices : 2
     Total Devices : 1
       Persistence : Superblock is persistent

       Update Time : Fri Nov 26 09:44:05 2021
             State : clean, degraded
    Active Devices : 1
   Working Devices : 1
    Failed Devices : 0
     Spare Devices : 0

Consistency Policy : resync

              Name : 2
              UUID : db8544d5:f3913fc6:b6f8d0e0:7265ecf1
            Events : 60271

    Number   Major   Minor   RaidDevice State
       3       8       19        0      active sync   /dev/sdb3
       -       0        0        1      removed

Nothing listed?

mdadm --assemble --scan

Well, my second disk is missing so

sudo mdadm --assemble /dev/md125 /dev/sdb3 --run ->

mdadm: /dev/md125 has been started with 1 drive (out of 2).

Another scan

`sudo lvmdiskscan`

->

/dev/sda1 [ 2,00 GiB] /dev/sda2 [ <215,01 GiB] LVM physical volume /dev/md125 [ <3,63 TiB] LVM physical volume 0 disks 1 partition 0 LVM physical volume whole disks 2 LVM physical volumes

Check for volume groups

sudo vgscan

WARNING: PV /dev/md125 in VG vg289 is using an old PV header, modify the VG to update.
Found volume group "vg289" using metadata type lvm2
Found volume group "rhel" using metadata type lvm2

Activate volume group

vgchange -a y vg289

Which logical volume?

sudo lvscan

WARNING: PV /dev/md125 in VG vg289 is using an old PV header, modify the VG to update.
ACTIVE '/dev/vg289/lv545' [37,16 GiB] inherit
ACTIVE '/dev/vg289/lv2' [3,59 TiB] inherit
...

the second looks interesting ...

Activate logical volume

sudo lvchange -a y vg289/lv2

WARNING: PV /dev/md125 in VG vg289 is using an old PV header, modify the VG to update.

Mount it

mkdir /mnt/rescuedisk

sudo mount -t ext4 /dev/vg289/lv2 /mnt/rescuedisk

Look for files

cd /mnt/rescuedisk

ls -l

CodeLoft

Friday, November 26, 2021

Mount QNAP Disk on Linux Server