xfs_repair an LVM on centos or other distros
For the first time I have started using LVM on my home server and things have been alright for an year. I am able to resize, replace disks , expand size of my mount points or move mount to a new disk without any trouble at all.
While its not relevant I am using CentOS 7.
I have had to force reboot the server a couple of times over the year and woefully XFS complained of corruption 24 hours ago and it was time to figure this out. I kept dropping into emergency mode upon reboot. There is also another reason for this problem. I have bad memory, I bought some refurbished FB-DIMM DDR2 with ECC and ironically not all of it is good.
Filesystem : XFS
Boot with rescue CD/USB whatever and dont mount anything
Using LVM? yes: Try with
lvscan to confirm
I Â run
xfs_repair /dev/sdx1 and it complains of bad superblock and it also fails to find a good secondary superblock. Something like `Sorry, could not find valid secondary superblock
Wait! IÂ need to repair from the VirtualÂ Volume
vgscan -v --mknodes
find and create
/dev/xxx/Â nodes for the lvm.
Now activate the volumes (it does not mount them)
vgchange -a y
Now see what volumes are active with another
/dev/centos/rootÂ which is what I need to fix. It is an XFS volume so this time I do
bunch of output follows…. repair is done.
Lets mount and test
mkdir /mnt/test && mount /dev/centos/root /mnt/test
Unmount and reboot without rescue CD.