ADIC Digital Camera 601355 Rev A 사용자 설명서

2-702

API Functions

601355 Rev A

VSCMD_Lock

 is issued to request execution of the VolServ 

Lock command.

The lock identifier assigned to the locked drive is returned to 
the client. This lock identifier must be used by clients on 
subsequent requests (such as Mount) for those drives.

A request to lock a drive that is busy (mounted or previously 
locked) queues until the drive becomes available. 

A Lock request that specifies a drive pool or a list of drives 
should also indicate the number of drives from the pool/list to 
be locked. VolServ selects the drives to lock from within the 
pool/list according to drive availability.

A Lock request cannot specify a drive pool or a list of drives 
that spans archives.

A Lock request reserves one drive for exclusive use, if a 
quantity is not specified on the command.

VolServ considers only on-line drives as candidates to be 
locked. If there is not a sufficient number of on-line drives in 
the same archive to satisfy a Lock request, the Lock request 
fails.

If there is a sufficient number of on-line drives in the same 
archive to satisfy a Lock request, but the number of available 
on-line drives is not sufficient, the request waits until sufficient 
drives become available. Partial locks are not set.

VST_BOOLEAN VSCMD_Lock 
( VST_COMMAND_HANDLE handle,
"…",
VSID_ENDFIELD )