Hi,
I have an RAID 6 array that is not having its 6 disks activated. Now
after reading more instructions it's clear that using webmin to create
RAID devices is a bad thing. You end up using the whole disk instead
of partitions of them.
All 6 disks should be ok and data should be clean. The array broke
after I moved the server to another location (sata cables might be in
different order etc). The original reason for the changes was an USB
drive that broke up... yep, there were the backups. That broken disk
was in fstab and therefore ubuntu went to recovery mode (since disk
was not available). So backups are now kind of broken too.
Autodiscovery does find the array:
RAID level - RAID6 (Dual Distributed Parity)
Filesystem status - Inactive and not mounted
Here's report from mdadm examine:
$ sudo mdadm --examine /dev/sd[c,b,d,e,f,g]
/dev/sdc:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : 2bf6381b:fe19bdd4:9cc53ae7:5dce1630
Name : NAS-ubuntu:0
Creation Time : Thu May 18 22:56:47 2017
Raid Level : raid6
Raid Devices : 6
Avail Dev Size : 7813782192 sectors (3.64 TiB 4.00 TB)
Array Size : 15627548672 KiB (14.55 TiB 16.00 TB)
Used Dev Size : 7813774336 sectors (3.64 TiB 4.00 TB)
Data Offset : 254976 sectors
Super Offset : 8 sectors
Unused Space : before=254896 sectors, after=7856 sectors
State : clean
Device UUID : b944e546:6c1c3cf9:b3c6294a:effa679a
Internal Bitmap : 8 sectors from superblock
Update Time : Wed Feb 28 19:10:03 2024
Bad Block Log : 512 entries available at offset 24 sectors
Checksum : 4a9db132 - correct
Events : 477468
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 5
Array State : AAAAAA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdb:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
/dev/sdd:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
/dev/sde:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
/dev/sdf:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
/dev/sdg:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
Since the disks have been used instead of partitions I'm now getting
an error when trying to assemble:
$ sudo mdadm --assemble /dev/md0 /dev/sdc /dev/sdb /dev/sdd /dev/sde
/dev/sdf /dev/sdg
mdadm: No super block found on /dev/sdb (Expected magic a92b4efc, got 00000000)
mdadm: no RAID superblock on /dev/sdb
mdadm: /dev/sdb has no superblock - assembly aborted
$ sudo mdadm --assemble --force /dev/md0 /dev/sdb /dev/sdc /dev/sdd
/dev/sde /dev/sdf /dev/sdg
mdadm: Cannot assemble mbr metadata on /dev/sdb
mdadm: /dev/sdb has no superblock - assembly aborted
Should I try to re-create that array again or how can I activate it
properly? It seems that only 1 disk reports the array information
correctly.
ls /dev/sd*
/dev/sda /dev/sda1 /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf
/dev/sdg /dev/sdh /dev/sdh1
All disks should be fine. I have setup a warning if any device fails
in the array and there have been no warnings. Also SMART data shows ok
for all disks.
Basic info:
$uname -a
Linux NAS-server 5.15.0-97-generic #107-Ubuntu SMP Wed Feb 7 13:26:48
UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
$mdadm --version
mdadm - v4.2 - 2021-12-30
$ sudo mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Raid Level : raid6
Total Devices : 1
Persistence : Superblock is persistent
State : inactive
Working Devices : 1
Name : NAS-ubuntu:0
UUID : 2bf6381b:fe19bdd4:9cc53ae7:5dce1630
Events : 477468
Number Major Minor RaidDevice
- 8 32 - /dev/sdc
So what should I do next?
I have not run the --create --assume-clean yet but could that help in this case?
Thanks for any help.
Best regards,
Topi Viljanen
