On 17/11/2021 12:22, Martin Thoma wrote:
Hi All,
So /dev/sdd1 was considered , when i ran the command again the raid
assembled without sdd1
When i tried Reading Data after a while it stopped (propably when the
data was on /dev/sdc
dmesg showed this:
[ 368.433658] sd 8:0:0:1: [sdc] tag#0 FAILED Result: hostbyte=DID_OK
driverbyte=DRIVER_SENSE
[ 368.433664] sd 8:0:0:1: [sdc] tag#0 Sense Key : Medium Error [current]
[ 368.433669] sd 8:0:0:1: [sdc] tag#0 Add. Sense: Unrecovered read error
[ 368.433675] sd 8:0:0:1: [sdc] tag#0 CDB: Read(16) 88 00 00 00 00 00
00 08 81 d8 00 00 00 08 00 00
[ 368.433679] blk_update_request: critical medium error, dev sdc, sector 557528
[ 368.433689] raid5_end_read_request: 77 callbacks suppressed
[ 368.433692] md/raid:md0: read error not correctable (sector 555480 on sdc1).
[ 375.944254] sd 8:0:0:1: [sdc] tag#0 FAILED Result: hostbyte=DID_OK
driverbyte=DRIVER_SENSE
and the Raided stopped again.
How can i force to assemble the raid including /dev/sdd1 and not
include /dev/sdc (because that drive is possibly damaged now)?
With a mdadm --create --assume-clean .. command?
NO NO NO NO NO !!!
I'm using mdadm/zesty-updates,now 3.4-4ubuntu0.1 amd64 [installed] on
Linux version 4.10.0-21-generic (buildd@lgw01-12) (gcc version 6.3.0
20170406 (Ubuntu 6.3.0-12ubuntu2) )
That's an old ubuntu? and an ancient mdadm 3.4?
As a very first action, you need to source a much newer rescue disk!
As a second action, if you think sdc and sdd are dodgy, then you need to
replace them - use dd or ddrescue to do a brute-force copy.
You don't mention what drives they are. Are they CMR? Are they suitable
for raid? For replacement drives, I'd look at upsizing to 4TB for a bit
of headroom maybe (or look at moving to raid 6). And look at Seagate
IronWolf, WD Red *PRO*, or Toshiba N300. (Personally I'd pass on the WD ...)
Once you've copied sdc and sdd, you can look at doing another force
assemble, and you'll hopefully get your array back. At least the event
count info implies damage to the array should be minimal.
https://raid.wiki.kernel.org/index.php/Linux_Raid#When_Things_Go_Wrogn
Read, learn, and inwardly digest ...
And DON'T do anything that will make changes to the disks - like a
re-create!!!
Cheers,
Wol
