Storage DRS generates space or I/O load balancing recommendations, but attempts to apply the recommendations fail.
When you apply Storage DRS recommendations for space or I/O load balancing, the operation fails.
The following scenarios can prevent you from applying Storage DRS recommendations.
A Thin Provisioning Threshold Crossed alarm might have been triggered for the target datastore, which indicates that the datastore is running out of space and no virtual machines will be migrated to it.
The target datastore might be in maintenance mode or is entering maintenance mode.
Address the issue that triggered the Thin Provisioning Threshold Crossed alarm.
Verify that the target datastore is not in maintenance mode or entering maintenance mode.