Is mdadm RAID Toast?
Solution 1
--create
will create an array, not assemble it - use --assemble
for that.
If that doesn't help, look at /proc/mdstat before going any further. Your examine output indicates all array members are present.
EDIT: Your drives sdc
and sdd
apparently have a protective MBR (indicated by partition type EE), i.e. they carry a GPT partition table. Maybe you are looking at the wrong disks, your kernel does not support GPT, or something overwrote the array headers?
Solution 2
For some reason, you seem to have used the whole disk for one of the drives, and a single partition on each of the other two. Try assembling using the partitions.
mdadm --assemble /dev/sdb /dev/sd[cd]1
Related videos on Youtube
Andrew Wei
Updated on September 18, 2022Comments
-
Andrew Wei almost 2 years
I took all my drives out and put them onto a new cpu/mobo. (upgrading)
I boot up and mdadm claims it can't boot my degraded RAID.
/dev/sdb
sudo mdadm --examine /dev/sdb /dev/sdb: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 91a6c44d:21226975:8d2dc41a:7fcff414 Name : desktop:0 (local to host desktop) Creation Time : Tue Jun 25 19:03:31 2013 Raid Level : raid5 Raid Devices : 3 Avail Dev Size : 5860271024 (2794.40 GiB 3000.46 GB) Array Size : 5860270080 (5588.79 GiB 6000.92 GB) Used Dev Size : 5860270080 (2794.39 GiB 3000.46 GB) Data Offset : 262144 sectors Super Offset : 8 sectors State : clean Device UUID : 367cb248:993e2658:ecd4b56d:2aaa0a6a Update Time : Tue Mar 4 17:48:54 2014 Checksum : d4572f50 - correct Events : 12635 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 1 Array State : AAA ('A' == active, '.' == missing)
/dev/sdc
sudo mdadm --examine /dev/sdc /dev/sdc: MBR Magic : aa55 Partition[0] : 4294967295 sectors at 1 (type ee)
/dev/sdd
sudo mdadm --examine /dev/sdd /dev/sdd: MBR Magic : aa55 Partition[0] : 4294967295 sectors at 1 (type ee)
What happens when I tried to "recreate" it
sudo mdadm --create /dev/md0 --level=5 --raid-devices=3 --spare-devices=0 /dev/sd[bcd] mdadm: /dev/sdb appears to be part of a raid array: level=raid5 devices=3 ctime=Tue Jun 25 19:03:31 2013 mdadm: /dev/sdc appears to be part of a raid array: level=raid0 devices=0 ctime=Wed Dec 31 18:00:00 1969 mdadm: partition table exists on /dev/sdc but will be lost or meaningless after creating array mdadm: /dev/sdd appears to be part of a raid array: level=raid0 devices=0 ctime=Wed Dec 31 18:00:00 1969 mdadm: partition table exists on /dev/sdd but will be lost or meaningless after creating array
I'm hoping there is a slight chance I can get my stuff back, considering mdadm doesn't see that sdc/sdd are part of a raid, but just not the same one.
Is my raid toast?
EDIT: Trying to assembling by specifying
sudo mdadm --assemble /dev/md0 /dev/sd[bcd] mdadm: no RAID superblock on /dev/sdc mdadm: /dev/sdc has no superblock - assembly aborted
Try Using --scan
sudo mdadm --assemble --scan mdadm: /dev/md0 assembled from 1 drive - not enough to start the array.
EDIT #2
cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : inactive sdb[1](S) 2930135512 blocks super 1.2 unused devices: <none>
EDIT #3
/dev/sdb
sudo gdisk -l /dev/sdb GPT fdisk (gdisk) version 0.8.7 Partition table scan: MBR: not present BSD: not present APM: not present GPT: not present Creating new GPT entries. Disk /dev/sdb: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): 76360B85-31EF-4155-8F9E-767C0C14454E Partition table holds up to 128 entries First usable sector is 34, last usable sector is 5860533134 Partitions will be aligned on 2048-sector boundaries Total free space is 5860533101 sectors (2.7 TiB) Number Start (sector) End (sector) Size Code Name
/dev/sdc
sudo gdisk -l /dev/sdc GPT fdisk (gdisk) version 0.8.7 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Disk /dev/sdc: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): DBD9F056-E1AE-4C22-826F-2D359EF6680E Partition table holds up to 128 entries First usable sector is 34, last usable sector is 5860533134 Partitions will be aligned on 2048-sector boundaries Total free space is 2925 sectors (1.4 MiB) Number Start (sector) End (sector) Size Code Name 1 2048 5860532223 2.7 TiB 0700
/dev/sdd
sudo gdisk -l /dev/sdd GPT fdisk (gdisk) version 0.8.7 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Disk /dev/sdd: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): BE9B843B-62CB-4D12-A661-5FA9AF871493 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 5860533134 Partitions will be aligned on 2048-sector boundaries Total free space is 2925 sectors (1.4 MiB) Number Start (sector) End (sector) Size Code Name 1 2048 5860532223 2.7 TiB 0700
-
ravi yarlagadda over 10 yearsYou should try to assemble instead of create - what's that get you?
-
Andrew Wei over 10 years@ShaneMadden I updated the post, it doesn't seem like it wants to assemble the raid.
-
-
Andrew Wei over 10 yearsWhen to assemble from scan or by specifying the drives, it doesn't like my raid.
-
ch2500 over 10 yearsWell, what's in /proc/mdstat?
-
Andrew Wei over 10 yearsSays there is one inactive drive, the others dont seem to be recognized as being part of it
-
Andrew Wei over 10 years
mdadm: no RAID superblock on /dev/sdc1
, same goes for /dev/sdd -
Andrew Wei over 10 yearsmy OS is the exact same install I was using a few hours ago. There are only 4 drives, a,b,c,d. A is OS, the rest are 3TB raid drives. The only thing that has changed is Motherboard & CPU. Thanks for your help, I appreciate it.
-
Andrew Wei over 10 yearsupdated edit #3
-
ch2500 over 10 yearsAww, something wrote a GPT with a Windows partition signature on those disks. Does your new board have some raid thingy? That might have done it. I suspect most of your data is still on the disks, but the header is now verrry damaged. Either ask a data recovery company, or a kernel hacker ;-)
-
Andrew Wei over 10 yearsI'll take that as ... "it's toast". Aww well