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RAID 5 relocation

It's time to relocate the good old RAID 5 to the new homelab server

Definition

RAID 5 consists of block-level striping with distributed parity. Unlike in RAID 4, parity information is distributed among the drives. It requires that all drives but one be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost.

Context

The RAID5 is constituted of four 2To HDD NAS Hard drive (WD Red Plus 2TB Internal Hard Drive 3.5" Dedicated NAS, 5400 RPM Class, SATA 6 GB/s, CMR, 64MB Cache). The RAID is known under the name md0.

To add a bit of challenge, thee server is randomly rebooting for unknown reasons

Procedure

First let's retrieve some informations about the actual installation

louison@turbonas:~/turbonas$ sudo mdadm --detail /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Wed Nov  2 23:45:02 2022
        Raid Level : raid5
        Array Size : 5860144128 (5588.67 GiB 6000.79 GB)
     Used Dev Size : 1953381376 (1862.89 GiB 2000.26 GB)
      Raid Devices : 4
     Total Devices : 4
       Persistence : Superblock is persistent

     Intent Bitmap : Internal

       Update Time : Sat Jan  3 22:06:21 2026
             State : clean 
    Active Devices : 4
   Working Devices : 4
    Failed Devices : 0
     Spare Devices : 0

            Layout : left-symmetric
        Chunk Size : 512K

Consistency Policy : bitmap

              Name : turbonas:0  (local to host turbonas)
              UUID : 694560c2:f5cfb9ed:f9b426fe:a0647876
            Events : 167869

    Number   Major   Minor   RaidDevice State
       0       8       33        0      active sync   /dev/sdc1
       1       8       49        1      active sync   /dev/sdd1
       3       8       65        2      active sync   /dev/sde1
       5       8        1        3      active sync   /dev/sda1

louison@turbonas:~/turbonas$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/ubuntu-vg/ubuntu-lv during curtin installation
/dev/disk/by-id/dm-uuid-LVM-kGozoEGlUCJzlum3ZYoECbC80V2ffiJ22ewGtR7F8qJaMheALEnxEst1ZJd02LMS / ext4 defaults 0 1
# /boot was on /dev/sdb2 during curtin installation
/dev/disk/by-uuid/514a4d2e-8fe6-4202-9579-927d20091322 /boot ext4 defaults 0 1
# /boot/efi was on /dev/sdb1 during curtin installation
/dev/disk/by-uuid/1767-5EBF /boot/efi vfat defaults 0 1
#/swap.img      none    swap    sw      0       0
/dev/md0    /media/raid    ext4    defaults    0    1

When I plugged the disks into the new server, I faced an issue with one disk. After testing data cable and power cable, I concluded that the issue was comming from the chinese M2 6SATA adapter.

Once I get all the disks connected, by some miracle, when I found out that the RAID had been automatically assemnbled.

Finally, I had to mount the RAID to the desired location and persist this mount in fstab.