Reserve (6); Table 6-93 Reserve Command - Sun Microsystems storagetek sl500 Reference Manual

Reserve (6)

Reserve (6)
The 6-byte Reserve command (16h) allows the initiator to perform unit reservations
or element reservations. Unit reservations are reservations of the library as a
whole. Element reservations are reservations of specific elements of the library.

TABLE 6-93 Reserve Command

Byte 7
0
1
2
3
to
4
5
Reserve (6) Command Definitions:
Element
Reservation
Identification
Element List Length
222 SL500: Interface Reference Manual • July 2008
6 5
Operation Code (16h)
Ignored
Reservation Identification
Element List Length
Control Byte (00h)
This bit indicates if the reserve is an element reserve. The library supports
reservation at the element level:
0 = The entire library unit is reserved.
■
1 = A series of elements—identified by the Reservation Identification field
■
and specified by the Element List Descriptor—is reserved.
This field is a value established by an initiator to identify a specific element
reservation request. The library supports a maximum of 64 element
reservations.
Note – Ignore this field if the Element bit is not set.
This field indicates the length in bytes of the Element List that follows the
command. The list may include a maximum of 16 Element List Descriptors, each
of which is 6 bytes long.
Valid values are 0, 6, and increments of 6 up to the maximum of 60h (96d).
If the value is 0 and the Element bit is set, no elements are reserved.
Note – Ignore this field if the Element bit is not set.
Bit
4 3 2
Obsolete (0h)
(MSB)
(LSB)
1 0
Element
Revision: F • 96122