On 07/31/2012 08:11 AM, NeilBrown wrote:
On Sat, 28 Jul 2012 13:46:06 +0200 Albert Pauw <albert.pauw@xxxxxxxxx> wrote:
Hi Neil,
After a hiatus of 1.5 year (busy with all sorts) I am back and tried the
ddf code to see how things improved.
Thanks!
I build a VM Centos 6.3 system with 6 extra 1GB disks for testing.
I found several issues in the standard installed 3.2.3 version of mdadm
relating to ddf, but installed the
3.2.5 version in order to work with recent code.
However, while version 3.2.3 is able to create a ddf container with
raidsets in it, I found a problem with the 3.2.5 version.
After initially creating the container:
mdadm -C /dev/md127 -e ddf -l container /dev/sd[b-g]
which worked, I created a raid (1 or 5 it doesn't matter in this case)
in it:
mdadm -C /dev/md0 -l raid5 -n 3 /dev/md127
However, it stays on resync=PENDING and readonly, and doesn't get build.
So I tried to set it to readwrite:
mdadm --readwrite /dev/md0
Unfortunately, it stays on readonly and doesn't get build.
As said before, this did work in 3.2.3.
Are you already on this problem?
It sounds like a problem with 'mdmon'. mdmon needs to be running before the
array can become read-write. mdadm should start mdmon automatically but
maybe it isn't. Maybe it cannot find mdmon?
could you check if mdadm is running? If it isn't run
mdmon /dev/md127 &
and see if it starts working.
Hi Neil,
thanks for your reply. Yes, mdmon wasn't running. Couldn't get it
running with a recompiled 3.2.5, the standard one which came with Centos
(3.2.3) works fine, I assume the made some changes to the code? Anyway,
I moved to my own laptop, running Fedora 16 and pulled mdadm frm git and
recompiled. That works. I also used loop devices as disks.
Here is the first of my findings:
I created a container with six disks, disk 1-2 is a raid 1 device, disk
3-6 are a raid 6 device.
Here is the table shown at the end of the mdadm -E command for the
container:
Physical Disks : 6
Number RefNo Size Device Type/State
0 06a5f547 479232K /dev/loop2 active/Online
1 47564acc 479232K /dev/loop3 active/Online
2 bf30692c 479232K /dev/loop5 active/Online
3 275d02f5 479232K /dev/loop4 active/Online
4 b0916b3f 479232K /dev/loop6 active/Online
5 65956a72 479232K /dev/loop1 active/Online
I now fail a disk (disk 0) and I get:
Physical Disks : 6
Number RefNo Size Device Type/State
0 06a5f547 479232K /dev/loop2 active/Online
1 47564acc 479232K /dev/loop3 active/Online
2 bf30692c 479232K /dev/loop5 active/Online
3 275d02f5 479232K /dev/loop4 active/Online
4 b0916b3f 479232K /dev/loop6 active/Online
5 65956a72 479232K /dev/loop1 active/Offline, Failed
Then I removed the disk from the container:
Physical Disks : 6
Number RefNo Size Device Type/State
0 06a5f547 479232K /dev/loop2 active/Online
1 47564acc 479232K /dev/loop3 active/Online
2 bf30692c 479232K /dev/loop5 active/Online
3 275d02f5 479232K /dev/loop4 active/Online
4 b0916b3f 479232K /dev/loop6 active/Online
5 65956a72 479232K active/Offline,
Failed, Missing
Notice the active/Offline status, is this correct?
I added the disk back into the container, NO zero-superblock:
Physical Disks : 6
Number RefNo Size Device Type/State
0 06a5f547 479232K /dev/loop2 active/Online
1 47564acc 479232K /dev/loop3 active/Online
2 bf30692c 479232K /dev/loop5 active/Online
3 275d02f5 479232K /dev/loop4 active/Online
4 b0916b3f 479232K /dev/loop6 active/Online
5 65956a72 479232K /dev/loop1 active/Offline,
Failed, Missing
It stays active/Offline (this is now correct I assume), Failed (again
correct if had failed before), but also still missing.
I remove the disk again, do a zero-superblock and add it again:
Physical Disks : 6
Number RefNo Size Device Type/State
0 06a5f547 479232K /dev/loop2 active/Online
1 47564acc 479232K /dev/loop3 active/Online
2 bf30692c 479232K /dev/loop5 active/Online
3 275d02f5 479232K /dev/loop4 active/Online
4 b0916b3f 479232K /dev/loop6 active/Online
5 ede51ba3 479232K /dev/loop1 active/Online, Rebuilding
This is correct, the disk is seen as a new disk and rebuilding starts.
Regards,
Albert
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