Virtual Machine with more than 64GB memory fails to Storage vMotion to vSAN cluster

An issue has been identified when trying to Storage vMotion a VM with a swap file larger than 64GB to the vSAN datastore.

This occurs as the swap file cannot be created on the vSAN datastore, as the size of the file exceeds the default limit for storage vMotion operations.

In the UI it can be identified by the following status failure: Failed waiting for data. Error 195887105. Failure.

KB 2150316 Contains more log samples and specifics for identifying the issue as a cause of a migration failure.









For now, the following workarounds can be used.

Set an advanced parameter on the destination ESXi host to increase the maximum memory allowed for the swap file.

To increase the swap file maximum size, run this command on the destination ESXi host:

# esxcfg-advcfg -s 0 /Mem/SwapExtendChunkSizeInMB

Note: Reboot is not required.

To reset it back to the default value after the SvMotion completes:

# esxcfg-advcfg -s 65536 /Mem/SwapExtendChunkSizeInMB

Jase Mccarty has a script to automate this setting across a cluster.

Setting a reservation of Memory on the Virtual machine and restarting it will shrink the swap file by the amount of the reservation.

As an example setting a 50GB Reservation on the memory of a virtual machine allocated 100GB will result in a swap file of 50GB. This smaller swap file will not encounter this issue during the migration.













Note: A reboot is required to shrink the swap file after setting the reservation.

Do a cold storage migration instead of a SvMotion.

Note: This requires the virtual machine to be powered off.



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