Fibre Channel Interface Manual, Rev. D 185

12.8 Lock-Unlock Cache (16) command

The Lock-Unlock Cache (16) command requests that the device server disallow or allow logical blocks within

the specified range to be removed from the cache memory by the device server's cache replacement algo-

rithm. Locked logical blocks may be written to the medium when modified, but a copy of the modified logical

block shall remain in the cache memory.

Multiple locks may be in effect from more than one application client. Locks from different application clients

may overlap. An unlock of an overlapped area does not release the lock of another initiator.

Table 119: Lock-Unlock Cache (16) command (92h)

Field definitions (listed alphabetically)
Control
See Control Bytes in Section 11.2.1.6.
Lock
0 All logical blocks in the specified range that are currently locked into the cache memory shall be unlocked, but may
not be removed.
1 Any logical block in the specified range that is currently present in the cache memory shall be locked into cache
memory. Only logical blocks that are already present in the cache memory are actually locked.
Number of Blocks
The number of contiguous logical blocks to be written.
0 indicates that all remaining logical blocks on the block device shall be within the range.
Bit
Byte
76543210
0Operation Code (92h)
1 Reserved Lock RelAdr
2 (MSB)
Logical Block Address
3
4
5
6
7
8
9(LSB)
10 (MSB)
Number of Blocks
11
12
13 (LSB)
14 Reserved
15 Control
92h
Table
number
119
119
119