When vMotioning a VM (specifically the .vswp file) residing on an NFS datastore you may see the following error.

vMotion fails with the error: remote host IP_Address failed with status Busy

This issue originally occurred in vSphere 4.1 but appears to have reappeared in vSphere 5.5 Update 2.

Luckily there is a workaround for now, until VMware can investigate and resolve the problem.

The workaround is to modify the advanced setting “Migrate.VMotionResolveSwapType” from the default of 1, to 0 on both the source and destination hosts. If you want to solve this for your entire cluster, then every host needs to be modified.

1. Launch the vSphere Client and log in to your vCenter Server.
2. Select the source ESX host and then click the Configuration tab.
3. Click Software > Advanced Settings > Migrate.
4. Under the Migrate options, locate the line containing Migrate.VMotionResolveSwapType. By default, it is set to 1.
5. Change the value to 0.
6. Click OK.
7. Repeat Steps 2 to 6 for all hosts in the cluster.

The official VMware KB is below.

vMotion fails with the error: remote host IP_Address failed with status Busy(1031636)