ADIC 601354 Command Priorities

Administrative Tasks

601354 Rev A Normal Operations 4-5

Normal Operation

Command Priorities

All VolServ commands are executed as they are sent. However,

a command queue keeps track of commands that arrive when

VolServ resources are busy.

Note that each command is associated with an execution

priority that ranges from 0 to 32 (high to low). The default

priority for each command is 15. Unless changed by a client, all

commands have a priority of 15. Commands with equal priority

are executed in a first-come first-served order.

To expedite a particular command in the queue when VolServ

resources are busy, the reprioritize request command is used.

When a command priority is changed to a higher value (that is,

numerically smaller), its position in the queue is moved closer

to first place.

Commands can be reprioritized via the GUI and API. The

reprioritize request parameters are the reprioritize request

identifier and new priority. The new priority replaces the

previous command priority in VolServ execution queue.

Any command in VolServ command queue, except the

dismount command, can be cancelled. Commands can be

cancelled via the GUI and API. The only cancel request

parameter is the cancel request identifier. When executed, the

command is removed from VolServ command queue.