2.6.29 - raid10 issue - spares do not get synched automatically
Hello,
I am using 2.6.29 on a debian lenny. Anyway, I am having problems with a raid10 sandbox setup consisting of 4 loopback devices. To make a long story short:
I created a raid10 array with all these 4 devices (loop0-loop3)
then I set two devices faulty, removed them .. checked if I can still write to the array (which I could, so I/O errors, nothing in dmesg):
BUT - here it comes: once I am trying to (re)add them (I zero'ed the superblock before) they're only getting added as spares and the array will not sync.
Here's the logfile with mdadm -D /dev/md0 in between so one can see what is going on:
http://paste.debian.net/31758/
Any ideas?
PS: Please CC to me since I am not subscribed.
regards,
Patrick
Quoted 10 lines · Patrick Ringl
Hello,
I am using 2.6.29 on a debian lenny. Anyway, I am having problems with a raid10 sandbox setup consisting of 4 loopback devices. To make a long story short:
I created a raid10 array with all these 4 devices (loop0-loop3) then I set two devices faulty, removed them .. checked if I can still write to the array (which I could, so I/O errors, nothing in dmesg):
Quoted 9 lines
BUT - here it comes: once I am trying to (re)add them (I zero'ed the superblock before) they're only getting added as spares and the array will not sync.
Here's the logfile with mdadm -D
/dev/md0in between so one can see what is going on:
Linux RAID10 with
Raid Level : raid10
Raid Devices : 4
Layout : near=2, far=1
Will layout data like this:
disk0 disk1 disk2 disk3
A A B B
C C D D
E E F FYou have removed disk0 and disk1, so A,C,E don't exist any more. You should get IO errors when you try to access that data.
There is nothing that can be recovered, so the drives remain as spares.
NeilBrown
Hello Neil,
Quoted 8 lines · NeilBrown
Linux RAID10 with
Raid Level : raid10
Raid Devices : 4Layout : near=2, far=1Will layout data like this:
Quoted 9 lines
disk0 disk1 disk2 disk3
A A B B C C D D E E F FYou have removed disk0 and disk1, so A,C,E don't exist any more. You should get IO errors when you try to access that data.
Sorry, but I removed loop0 and loop2 so that would be disk0 and disk2 - so ACE as well as BDF should still exist and recover. Could you explain this, I am I just getting you wrong?
Quoted 5 lines
There is nothing that can be recovered, so the drives remain as spares.
NeilBrown
regards,
Patrick
Hello Neil,
Quoted 14 lines · NeilBrown
Linux RAID10 with
Raid Level : raid10
Raid Devices : 4Layout : near=2, far=1Will layout data like this:
disk0 disk1 disk2 disk3
A A B B C C D D E E F F
Quoted 7 lines
You have removed disk0 and disk1, so A,C,E don't exist any more. You should get IO errors when you try to access that data.
There is nothing that can be recovered, so the drives remain as spares.NeilBron
You're right - sorry. I better should read my own logfiles tho. Somehow removing a single disk and readding it mixed up with the raid device numbering - which I didnt notice at first.
regards,
Patrick
Quoted 16 lines · Patrick Ringl
Hello Neil,
Quoted 13 lines · NeilBrown
Linux RAID10 with
Raid Level : raid10
Raid Devices : 4Layout : near=2, far=1Will layout data like this:
disk0 disk1 disk2 disk3
A A B B C C D D E E F F
Quoted 7 lines
Quoted 4 lines
You have removed disk0 and disk1, so A,C,E don't exist any more. You should get IO errors when you try to access that data.
Sorry, but I removed loop0 and loop2 so that would be disk0 and disk2 - so ACE as well as BDF should still exist and recover. Could you explain this, I am I just getting you wrong?
From the Pastezone thing...
-----------------------------------------------------
Number Major Minor RaidDevice State
0 7 2 0 active sync /dev/loop2
1 7 0 1 active sync /dev/loop0
2 7 1 2 active sync /dev/loop1
3 7 3 3 active sync /dev/loop3
pari:/mnt/debian# mdadm --manage /dev/md0 -f /dev/loop2 mdadm: set /dev/loop2 faulty in /dev/md0 pari:/mnt/debian# mdadm --manage /dev/md0 -f /dev/loop0 mdadm: set /dev/loop0 faulty in /dev/md0 ---------------------------------------------------
So while you did remove loop0 and loop2, these were disk1 and disk0.
NeilBrown