Hello, all!
I am new to the mailing list and looking to learn all I can about
linux software raid systems, especially how to recover broken raid
setups.
I have a broken raid10 array to work on as a test case. The origanal
array consisted of 4 partitions, each on a separate disk. Two of the
disks also have a raid0 array in two partitions. One of the disks is
in a SMART bad state and is not showing in lsblk. I tried to remove
and re-add what I thought was the failing member before it was
disabled by the BIOS. I did somehting wrong and I now have an array in
an unassembleable state. One of the three remaining members believes
it is trying to resync. As far as I can tell it hasn't actually
changed the data on the disk, only the superblock data. It went into a
resync/restart loop where it would "resync" every couple of seconds.
Obviously this is not enough time to resync ~100GB.
Once I realized it wasn't working I stopped everything and made full
images of the three good disks. After that I tried following the
instructions in Recovering_a_damaged_RAID. I created the overlay files
and tried creating a raid0 array by trying every combination of two of
the three available members. Unfortunately it seems I have two good
copies of the first half of a striped array, one copy of the second
half in an unknown state on a good disk, and another copy of the
second half in a good state on a bad disk.
At this point I need to know if I would be better off trying to read
the data from the bad disk (which I haven't touched up to this point)
or to try and somehow realign the data on the good disk. The data is
mostly backed up (I'd lose a little work but nothing terrible). I will
post all of the metadata I have below.
Any help/info/encouragement would be greatly apprecaited. Also, any
books/websites/training recommendations would be welcomed as well.
/dev/sda:
MBR Magic : aa55
Partition[0] : 225280000 sectors at 2048 (type 83)
Partition[1] : 81920000 sectors at 225282048 (type 83)
/dev/sda1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : 594b6aa2:f5adf1f0:8eb3593e:7e5ee197
Name : HammerheadLubuntu:10
Creation Time : Fri Apr 3 17:05:21 2015
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 225148928 (107.36 GiB 115.28 GB)
Array Size : 225148928 (214.72 GiB 230.55 GB)
Data Offset : 131072 sectors
Super Offset : 8 sectors
Unused Space : before=130984 sectors, after=0 sectors
State : clean
Device UUID : af7f6b0f:55429546:8b349e8e:bf7e41bf
Internal Bitmap : 8 sectors from superblock
Update Time : Mon Oct 1 17:52:13 2018
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : 6f15fdda - correct
Events : 43197
Layout : near=2
Chunk Size : 512K
Device Role : Active device 2
Array State : R.A. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sda2:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 1efd3d44:9c119eba:2a46ccef:41a511c1
Name : HammerheadLubuntu:0
Creation Time : Fri Apr 3 17:11:58 2015
Raid Level : raid0
Raid Devices : 2
Avail Dev Size : 81854464 (39.03 GiB 41.91 GB)
Data Offset : 65536 sectors
Super Offset : 8 sectors
Unused Space : before=65448 sectors, after=0 sectors
State : clean
Device UUID : dfc4efdb:85bb3a6a:ceebeded:f20b90e8
Update Time : Fri Apr 3 17:11:58 2015
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : e177b242 - correct
Events : 0
Chunk Size : 512K
Device Role : Active device 1
Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdb:
MBR Magic : aa55
Partition[0] : 225280000 sectors at 2048 (type 83)
/dev/sdb1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1b
Array UUID : 594b6aa2:f5adf1f0:8eb3593e:7e5ee197
Name : HammerheadLubuntu:10
Creation Time : Fri Apr 3 17:05:21 2015
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 225148928 (107.36 GiB 115.28 GB)
Array Size : 225148928 (214.72 GiB 230.55 GB)
Data Offset : 131072 sectors
Super Offset : 8 sectors
Recovery Offset : 0 sectors
Unused Space : before=130984 sectors, after=0 sectors
State : clean
Device UUID : 05aa2ed1:e018cbd9:9cb92c4c:dc28d89f
Internal Bitmap : 8 sectors from superblock
Update Time : Mon Oct 1 17:52:13 2018
Bad Block Log : 512 entries available at offset 72 sectors - bad
blocks present.
Checksum : 62342e05 - correct
Events : 43197
Layout : near=2
Chunk Size : 512K
Device Role : Replacement device 0
Array State : R.A. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdc:
MBR Magic : aa55
Partition[0] : 225280000 sectors at 2048 (type 83)
Partition[1] : 81920000 sectors at 225282048 (type 83)
/dev/sdc1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x1
Array UUID : 594b6aa2:f5adf1f0:8eb3593e:7e5ee197
Name : HammerheadLubuntu:10
Creation Time : Fri Apr 3 17:05:21 2015
Raid Level : raid10
Raid Devices : 4
Avail Dev Size : 225148928 (107.36 GiB 115.28 GB)
Array Size : 225148928 (214.72 GiB 230.55 GB)
Data Offset : 131072 sectors
Super Offset : 8 sectors
Unused Space : before=130984 sectors, after=0 sectors
State : clean
Device UUID : 3573dafb:d68bc34c:18c37e5d:11eee210
Internal Bitmap : 8 sectors from superblock
Update Time : Mon Oct 1 17:00:15 2018
Bad Block Log : 512 entries available at offset 72 sectors
Checksum : 823b0797 - correct
Events : 33733
Layout : near=2
Chunk Size : 512K
Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
