VM Disk Migration Fails with I/O Read Error

[powersupport]

Hi Support Team,

We’re facing an issue while migrating a VM disk. The migration starts but fails part way with an I/O read error from the source NAS storage.

Here’s the error:


moving disk with snapshots, snapshots will not be moved!
create full clone of drive scsi0 (NAS-BACKUP:125/vm-125-disk-0.qcow2)
transferred 0.0 B of 1.0 TiB (0.00%)
transferred 10.2 GiB of 1.0 TiB (1.00%)
transferred 20.5 GiB of 1.0 TiB (2.00%)
transferred 30.7 GiB of 1.0 TiB (3.00%)
transferred 41.0 GiB of 1.0 TiB (4.00%)
transferred 51.2 GiB of 1.0 TiB (5.00%)
qemu-img: error while reading at byte 21696741376: Input/output error

The migration fails consistently at around 21 GB, which appears to be a read issue on the source disk.


Could you please advise why this issue occurs and how we can resolve it?


Thank you.

 

[uzumo]

I believe the data is corrupted.

This occurred with ZFS created on a single disk or other file systems.
*When creating ZFS on a single disk, it will also stop in the same state when encountering the ZFS-8000-8A error.

It rarely happens with zpool mirrors, as it can often be fixed with scrub.

If you can boot from the original disk, you can recover by taking a backup from the guest and creating a disk.