Today’s VCDX note is just a general note about VMFS volume SCSI-2 Reservations. As you may know, VMFS is a clustered file system. It allows multiple hosts to read and write to the same VMFS volume simultaneously. This is accomplished through a mechanism called distributed lock handling. Distributed lock handling locks individual files instead of an entire VMFS volume.
For example, file locks are put on files associated with a VM so that it can only be powered on by one host at a time. However, there are occasions that the entire volume must be reserved using a SCSI-2 Reservation (e.g. a VMFS volume Metadata update). The short video below shows how you can observe this behavior in your own testing by administratively locking the VMFS volume with the vmkfstools command.
{ 1 trackback }
{ 0 comments… add one now }