The Enterprise Vault server is running out of disk space in a particular index location...

manually move the Index files to the new location > run the "Synchronize" task

use the "Index Volumes Browser" and choose the index volume > click the "Move" button

run the "Change Location" task > manually copy the Index files to the new location

manually move the Index files to the new location > change the path in the IndexServiceEntry table in the EV directory database