API Guide
601355 Rev A API Functions 2-649
Functions
Mounted drives that have their state changed remain in-use;
varying a drive has no impact on client data transfer operations
in progress, and the client receives no automatic notification of
a drive state change.
Drives can be varied regardless of whether or not they are
associated with an archive.
Drives can be varied regardless of whether or not they are
allocated; however, allocated drives that are not on-line
cannot be dismounted.
Drives can be varied by an operator and over the client interface
into the off-line, on-line, and diagnostic states
only.
The unavailable state is only assignable by VolServ when
a higher level component in the archive system is no longer
on-line. For example, varying a CLM off-line causes
the associated drive to be viewed as unavailable.
The VSID_DRIVE_ID_LIST and
VSID_COMP_STATE_LIST parameters require that two
arguments be passed instead of one.
All parameters can be set for the specific request being sent by
passing them to this function, or they can be set for all Drive
Vary requests using the
VSCMD_DriveVary_SetDefaults command.
It is possible to vary drives to different states with one request.
To do this, use the VSID_DRIVE_ID_LIST and
VSID_COMP_STATE_LIST parameters.
The total length of time the API software waits for a command
status in synchronous mode from VolServ is
(VSID_RETRY_LIMIT plus 1) multiplied by
VSID_TIMEOUT_VALUE.