lvm superblock misdetection in conjunction with degraded softraid
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| lvm2 (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
Bug Description
Binary package hint: lvm2
Hi,
I am running a raid5 with 5 devices: /dev/sda1 /dev/sdb1 ... /dev/sde1, these are assembled to run /dev/md0. Chunk size is 128k. /dev/md0 contains a lvm2 physical volume, which contains a volume group with some logical volumes.
When I remove /dev/sda1 (by setting it faulty or change the partiton type) from /dev/md0 weird things happen:
lvm sees a lvm header in a raid stripe on /dev/sda1 and tries to load some logical volumes from /dev/sda1 only which then contain only random raid stripe garbage. Some other logical volumes are loaded from /dev/md0. When I physically remove /dev/sda or zero out the first gigabyte on /dev/sda or remove the /dev/sda1 partition everything works fine again.
What I expected was that lvm ignores the broken lvm headers on /dev/sda1 and load everything from /dev/md0.
If you need additional info for reproducing this bug please let me know and i will try to reproduce it under controlled conditions in a virtual machine.
cheers,
Markus
