# QEMU Image Lock Fail to Start VMs After Host Crashes

## Problem

Migrated or Evacuated VMs fail to start on destination host when the source host crashes. The following error is observed in log */var/log/pf9/ostackhost.log.*

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```none
569 ERROR nova.virt.libvirt.driver [req-7638759c-10a6-40c5-86f9-4bda4b2dfb82 masakari services] [instance: 65c55b81-9078-44b4-bb07-95dc5adeadba] Failed to start libvirt guest: internal error: qemu unexpectedly closed the monitor: 2019-10-28T00:39:09.301445Z qemu-kvm: -drive file=/mnt/nfs/instances/65c55b81-9078-44b4-bb07-95dc5adeadba/disk,format=qcow2,if=none,id=drive-virtio-disk0,cache=none: Failed to get "write" lock
```

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## Environment

* Platform9 Managed OpenStack - v3.6.0 and Higher
* NFSv3
* QEMU

## Cause

* Limitation in NFSv3.

## Solution

1. Wait for the crashed host to come back online.
2. Once the crashed host is online, reboot the VMs which failed to get a write-lock.

## Additional Information

[Bug details](https://bugzilla.redhat.com/show_bug.cgi?id=1547095)


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