* BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving
@ 2005-05-03 11:02 Tyler
2005-05-03 23:50 ` Neil Brown
0 siblings, 1 reply; 3+ messages in thread
From: Tyler @ 2005-05-03 11:02 UTC (permalink / raw)
To: linux-raid, neilb
On a site note, mdadm --zero-superblock doesn't seem to work correctly
with mdadm v2.0-devel, it reports no error when you use it, but you can
mdadm -E /dev/hdX after using it, and there is still a superblock, if
you use mdadm v1.9.0-2, it works correctly, and the examine shows
nothing afterwards. Examples follow after the first problem. Mdadm
v2.0 also seems to misreport the findings using the examine function..
"381 spares." Using kernel 2.6.12-rc3-mm2.
First i run zero superblock with mdadm v2.0-devel from current dir:
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
Then examine the superblock using mdadm v2.0-devel from current dir:
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc
/dev/hdc:
Magic : a92b4efc
Version : 01.00
Array UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Name :
Creation Time : Tue May 3 11:16:22 2005
Raid Level : raid5
Raid Devices : 3
Device Size : 390721952 (186.31 GiB 200.05 GB)
Super Offset : 390721952 sectors
State : active
Device UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Update Time : Tue May 3 11:16:22 2005
Checksum : d4cd5d80 - correct
Events : 0
Layout : -unknown-
Chunk Size : 64K
Array State : Uuu 381 spares
Then i try using mdadm v1.9.0 (from system path):
root@localhost:~/dev/mdadm-2.0-devel-1# mdadm --version
mdadm - v1.9.0 - 04 February 2005
root@localhost:~/dev/mdadm-2.0-devel-1# mdadm -E /dev/hdc
mdadm: No super block found on /dev/hdc (Expected magic a92b4efc, got
00000000)
Then i try erasing the superblock again with mdadm v1.9.0 from system path:
root@pink:~/dev/mdadm-2.0-devel-1# mdadm --version
mdadm - v1.9.0 - 04 February 2005
root@pink:~/dev/mdadm-2.0-devel-1# mdadm --zero-superblock /dev/hdc
mdadm: /dev/hdc does not appear to have an MD superblock.
Then examine it again with mdadm v2.0-devel from current dir:
root@pink:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc
/dev/hdc:
Magic : a92b4efc
Version : 01.00
Array UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Name :
Creation Time : Tue May 3 11:16:22 2005
Raid Level : raid5
Raid Devices : 3
Device Size : 390721952 (186.31 GiB 200.05 GB)
Super Offset : 390721952 sectors
State : active
Device UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Update Time : Tue May 3 11:16:22 2005
Checksum : d4cd5d80 - correct
Events : 0
Layout : -unknown-
Chunk Size : 64K
Array State : Uuu 381 spares
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving
2005-05-03 11:02 BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving Tyler
@ 2005-05-03 23:50 ` Neil Brown
2005-05-03 23:55 ` Tyler
0 siblings, 1 reply; 3+ messages in thread
From: Neil Brown @ 2005-05-03 23:50 UTC (permalink / raw)
To: Tyler; +Cc: linux-raid
On Tuesday May 3, pml@dtbb.net wrote:
> On a site note, mdadm --zero-superblock doesn't seem to work correctly
> with mdadm v2.0-devel, it reports no error when you use it, but you can
> mdadm -E /dev/hdX after using it, and there is still a superblock, if
> you use mdadm v1.9.0-2, it works correctly, and the examine shows
> nothing afterwards. Examples follow after the first problem. Mdadm
> v2.0 also seems to misreport the findings using the examine function..
> "381 spares." Using kernel 2.6.12-rc3-mm2.
>
> First i run zero superblock with mdadm v2.0-devel from current dir:
>
> root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
>
> Then examine the superblock using mdadm v2.0-devel from current dir:
>
> root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc
> /dev/hdc:
> Magic : a92b4efc
> Version : 01.00
What has happened here is that "mdadm --zero-superblock" found a
version 0.90 superblock and zeroed it. There was still a version 1
superblock (which lives in a different location). and -E found that.
If you run --zero-superblock serveral times it should zero everything,
though normally you would not expect to have multiple superblocks.
>
> Array State : Uuu 381 spares
>
Not sure about this. I'll have to spend a while reminding my self
what is meant to happen, and what actually does...
NeilBrown
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving
2005-05-03 23:50 ` Neil Brown
@ 2005-05-03 23:55 ` Tyler
0 siblings, 0 replies; 3+ messages in thread
From: Tyler @ 2005-05-03 23:55 UTC (permalink / raw)
To: Neil Brown; +Cc: linux-raid
Hi Neil,
I tried removing the superblock several times to test the theory, but it
seems the removal isn't working.. maybe because of the semi-invalid
information of 380 spare drives? I'm not sure?
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc
/dev/hdc:
Magic : a92b4efc
Version : 01.00
Array UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Name :
Creation Time : Tue May 3 11:16:22 2005
Raid Level : raid5
Raid Devices : 3
Device Size : 390721952 (186.31 GiB 200.05 GB)
Super Offset : 390721952 sectors
State : active
Device UUID : f4b2dc026e:a3cc3e95:de0563f5:199250
Update Time : Tue May 3 11:16:22 2005
Checksum : d4cd5d80 - correct
Events : 0
Layout : -unknown-
Chunk Size : 64K
Array State : Uuu 381 spares
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdd
root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdd
mdadm: Unrecognised md component device - /dev/hdd
Neil Brown wrote:
>On Tuesday May 3, pml@dtbb.net wrote:
>
>
>>On a site note, mdadm --zero-superblock doesn't seem to work correctly
>>with mdadm v2.0-devel, it reports no error when you use it, but you can
>>mdadm -E /dev/hdX after using it, and there is still a superblock, if
>>you use mdadm v1.9.0-2, it works correctly, and the examine shows
>>nothing afterwards. Examples follow after the first problem. Mdadm
>>v2.0 also seems to misreport the findings using the examine function..
>>"381 spares." Using kernel 2.6.12-rc3-mm2.
>>
>>First i run zero superblock with mdadm v2.0-devel from current dir:
>>
>>root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm --zero-superblock /dev/hdc
>>
>>Then examine the superblock using mdadm v2.0-devel from current dir:
>>
>>root@localhost:~/dev/mdadm-2.0-devel-1# ./mdadm -E /dev/hdc
>>/dev/hdc:
>> Magic : a92b4efc
>> Version : 01.00
>>
>>
>
>What has happened here is that "mdadm --zero-superblock" found a
>version 0.90 superblock and zeroed it. There was still a version 1
>superblock (which lives in a different location). and -E found that.
>If you run --zero-superblock serveral times it should zero everything,
>though normally you would not expect to have multiple superblocks.
>
>
>
>> Array State : Uuu 381 spares
>>
>>
>>
>
>Not sure about this. I'll have to spend a while reminding my self
>what is meant to happen, and what actually does...
>
>NeilBrown
>
>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2005-05-03 11:02 BUGREPORT: mdadm v2.0-devel - Examine and zero-superblock misbehaving Tyler
2005-05-03 23:50 ` Neil Brown
2005-05-03 23:55 ` Tyler
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