vQuicky – For the impatient like me

> Too many disk operations on a datastore will lead to storage vmotion time out to occur

> The time out is a consequence of overhead per disk during storage vmotion. Over head involves opening, closing and processing disks

> Default time out is 100 seconds but can be increased by adding a parameter fsr.maxSwitchoverSeconds

> To add the row – power off the virtual machine –>in Options tab –>Advanced general –> Configuration parameters —–>Add row

> If manually editing the .vmx file, remember to remove the virtual machine from inventory first, modify .vmx and then re-add it back


In my lab I was moving many virtual machines around and got this error.

“The migration has exceeded the maximum switchover time of 100 second(s). ESX has preemptively failed the migration to allow the VM to continue running on the source.  To avoid this failure, either increase the maximum allowable switchover time or wait until the VM is performing a less intensive workload.”

This happens when a Virtual Machine with many disks is unable to complete Storage vmotion. In my case, I had a high latency FREENAS box hosting iscsi luns and in an attempt to rebuild it, I was moving many machines to local hypervisor disks. Remember that storage vmotion requires time to open, close and process disks in its final copy phase. So storage vmotion working on many disks will timeout because of this over head. So basically, large number of operations occurring on the same datastore will cause it to timeout.

To fix this we increase the fsr.maxSwitchoverSeconds to more than 100 seconds which is the default. To do this you will have to power down the machine –> Edit settings –> Options Tab –> Advanced general –> Configuration parameters –> Add row and add the “fsr.maxSwitchoverSeconds = 200”

Remember if you are manually editing the .vmx file, power off the virtual machine, remove it from the inventory – modify the .vmx file and then re-add it to the inventory.

Please do comment or correct me 🙂

Leave a Reply

Your email address will not be published.

Post Navigation