KVM: Fail to migrate VM with local root disk and datadisk attached

[GabrielBrascher]

ISSUE TYPE

• Bug Report

COMPONENT NAME

API

CLOUDSTACK VERSION

4.16

CONFIGURATION

• KVM
• Root disk on Local storage
• DataDisk allocated on any shared storage (tested on NFS, RBD)

OS / ENVIRONMENT

SUMMARY

When migrating a VM with root disk in local storage + datadisk (always shared) it fails.
There are two ways of performing such a migration via the migrateVirtualMachineWithVolume.

1. migrate virtualmachinewithvolume virtualmachineid=<VM_ID> hostid=<HOST_ID>
2. migrate virtualmachinewithvolume virtualmachineid=<VM_ID> hostid=<HOST_ID> migrateto[0].volume=<VOLUME_ID> migrateto[0].pool=<POOL_ID>

In the first case, the execution flow has no mapped volumes; however, it assumes that all the volumes on the VM should be migrated and maps such migrations. Causing exception during migration as the data disk has the wrong map.

In the second scenario, CloudStack holds the provided map of volume -> storages but at the end, it turns out to try to migrate all the volumes ignoring the provided map.

STEPS TO REPRODUCE

Migrate a VM with at least 1 Datadisk and its Root disk allocated in local storage.

EXPECTED RESULTS

VM is live-migrated along with its Root disk to another host (& respective local storage pool) in the same cluster

ACTUAL RESULTS

Fails to migrate VM

[shwstppr]

@GabrielBrascher are these scenarios working fine on 4.15?

[GabrielBrascher]

@shwstppr I am testing and debugging it in 4.16. But, as far as I know, 4.15 (and 4.14) also present issues in such migrations.

[GabrielBrascher]

@shwstppr I have created PR #5410 addressing this issue. Can you please check it? Thanks!

[sureshanaparti]

Closing the issue, as the associated fix PR is merged.