About the vos command line tool category

The commands in the vos command suite are the administrative interface to the Volume Server and Location Service. Cell administrators use vos commands to create, move, delete, replicate, back up and examine volumes, among other operations. The Location Service automatically records changes in volume status and location that result from vos commands.

The operations invoked by most vos commands are idempotent, meaning that if an operation is interrupted due to network outage or server failure, then a subsequent attempt at the same operation continues from the interruption point, rather than starting over at the beginning of the operation. The vos command checks with the Volume Server and Location Service to verify the current state of the volumes and their location information.

If the volumes and associated location information are already in the desired end state (or a consistent intermediate state), there is no need to repeat the internal steps that brought them there. Idempotency does not apply if the command issuer explicitly interrupts the operation with Ctrl-C or another interrupt signal. In that case, the volume is left locked and the cell administrator must use the vos_unlock(1) command to unlock it before proceeding.

It is important that the Location Service accurately indicate the status of the volumes on File Servers at all times. If a vos command changes volume status, it notifies the Location Service. The most common cause of discrepancies between the state of a volume as reported by the Location Service and the volume status known to the File Servers is interrupted operations. To restore consistency, use the vos_syncfs(1) and vos_syncloc(1) commands.

There are several categories of commands in the vos command suite:

Use this category to discuss the use of the vos command suite.