Load network block device module:
# modprobe nbd max_part=8
Poweroff machine:
# virsh destroy virtual-machine
Connect disk image:
# qemu-nbd --connect=/dev/nbd0 /var/lib/libvirt/images/virtual-machine.qcow2
Check disk:
# fsck /dev/nbd0p1
fsck from util-linux 2.25.2
e2fsck 1.42.12 (29-Aug-2014)
/dev/nbd0p1: recovering journal
/dev/nbd0p1 contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Inodes that were part of a corrupted orphan linked list found. Fix<y>? yes
Inode 274 was part of the orphaned inode list. FIXED.
Inode 132276 was part of the orphaned inode list. FIXED.
Deleted inode 142248 has zero dtime. Fix<y>? yes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Block bitmap differences: -603674 -623174 +(689342--689343)
Fix<y>? yes
Free blocks count wrong for group #18 (15076, counted=15077).
Fix<y>? yes
Free blocks count wrong for group #19 (11674, counted=11675).
Fix<y>? yes
Free blocks count wrong (632938, counted=670871).
Fix<y>? yes
Inode bitmap differences: -274 -132276 -142248
Fix<y>? yes
Free inodes count wrong for group #0 (52, counted=53).
Fix<y>? yes
Free inodes count wrong for group #16 (99, counted=100).
Fix<y>? yes
Free inodes count wrong for group #17 (519, counted=520).
Fix<y>? yes
Free inodes count wrong (204392, counted=204599).
Fix<y>? yes
/dev/nbd0p1: ***** FILE SYSTEM WAS MODIFIED *****
/dev/nbd0p1: 101833/306432 files (0.2% non-contiguous), 553321/1224192 blocks
Disconnect device:
# qemu-nbd --disconnect /dev/nbd0
/dev/nbd0 disconnected
Start machine:
# virsh start virtual-machine
Thank you! That was really helpful!
Although damaged root partition was 1M in size and recovery partition was about 100M, so I was unable to write it. I guess it's something related to COW and how one disk based on another one.