Product manual

SCSI Description
Maxtor Atlas 10K IV 5-85
Table 5-117 presents the definitions of the characters of the available “Type” values
from the Type field of the PERSISTENT RESERVATION IN Read Reservations
parameters.
Each of the codes provides handling instructions for READ operations, for WRITE
operations, and for subsequent attempts to establish persistent reservations (referred
to as “Additional Reservations Allowed” in the table).
Table 5-117 Persistent Reservation Type Codes and Their Meanings
Code Name Description
0h READ Shared
READS: Shared; any application client on any initiator may execute commands that
perform transfers from the disk to the initiator.
WRITES: Prohibited; any command from any initiator that performs a transfer from the
initiator to the disk results in a reservation conflict.
ADDITIONAL RESERVATIONS: Allowed; any initiator may reserve the logical unit,
extents, or elements as long as the persistent reservations do not conflict with any res-
ervations already known to the device server.
1h
WRITE Exclu-
sive
READS: Shared; any application client on any initiator may execute commands that
perform transfers from the disk to the initiator.
WRITES: Exclusive; any command from any initiator other than the initiator that holds
the persistent reservation that attempts a transfer to the disk results in a reservation con-
flict
ADDITIONAL RESERVATIONS: Allowed; any initiator may reserve the logical unit,
extents, or elements as long as the persistent reservations do not conflict with any res-
ervations already known to the device server.
2h READ Exclusive
READS: Exclusive; any command from any initiator other than the initiator that holds
the persistent reservation that attempts a transfer from the disk results in a reservation
conflict
WRITES: Shared; any application client on any initiator may execute commands that
perform transfers to the disk from the initiator.
ADDITIONAL RESERVATIONS: Allowed; any initiator may reserve the logical unit,
extents, or elements as long as the persistent reservations do not conflict with any res-
ervations already known to the device server.
3h Exclusive Access
READS: Exclusive; any command from any initiator other than the initiator holding the
persistent reservation that attempts a transfer from the disk results in a reservation con-
flict.
WRITES: Exclusive; any command from any initiator other than the initiator holding
the persistent reservation that attempts a transfer to the disk results in a reservation con-
flict.
ADDITIONAL RESERVATIONS: Restricted; any PERSISTENT RESERVATION
OUT command with the Reserve service action from any initiator other than the initiator
holding the persistent reservation results in a reservation conflict. The initiator that
holds the persistent reservation can reserve the logical unit, extents, or elements as long
as the persistent reservations do not conflict with any reservations already known to the
device server.