Ming,

Reservations and persistent reservations are both I_T nexus based. The question that has to be answered is; What has the iSCSI protocol defined as the initiator port (i.e., the I) and the target port (i.e., the T). From SAMs point of view as long as the connection is between the same I and T that holds the reservation then the command is valid regardless of the actual physical path that is used (i.e., there can be any number of physical paths between a single initiator port and a single target port).

Bye for now,
George Penokie

Dept 9A8 030-3 A410
E-Mail: gop@us.ibm.com
Internal: 553-5208
External: 507-253-5208

Ming Zhang <blackmagic02881@gmail.com>
Sent by: owner-t10@t10.org

12/28/2006 10:21 AM

Please respond to
blackmagic02881@gmail.com

To	t10@t10.org
cc	Arne Redlich <agr@powerkom-dd.de>, Juhani Rautiainen <jrauti@iki.fi>, Steffen Plotner <swplotner@amherst.edu>, "Ross S. W. Walker" <rwalker@medallion.com>
Subject	question about reservation and persistent reservation

* From the T10 Reflector (t10@t10.org), posted by: * Ming Zhang <blackmagic02881@gmail.com> * Hi All We try to add reservation support to an iSCSI target and have some questions about reservation. Reservation is per nexus or per initiator? persistent reservation is per nexus or per initiator? Our dilemma is like this. between an iSCSI initiator and target, multipath IO can (1) has multiple sessions over to same target via different physical NICs and paths. or (2) has one session with multiple connections, with each connection over different paths. Base on iSCSI RFC, (1) will have multiple I_L nexus while (2) only have 1 nexus. Then for reservation support via RESERVE_6/10, if one initiator reserve one LU via one session, can this initiator send WRITE or other commands via another session? Thanks Ming * * For T10 Reflector information, send a message with * 'info t10' (no quotes) in the message body to majordomo@t10.org