From 6b3ad5d0fe9c9d7d1330dc3ea5f72dbc37828687 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 17 May 2011 19:28:56 +0000 Subject: [PATCH] Refined ALUA documentation: - Added pointer to information about associating iSCSI targets with network interfaces. - Added information about configuring ALUA multipath on a Linux initiator. git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@3457 d57e44dd-8a1f-0410-8b47-8ef2f437770f --- scst/README | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/scst/README b/scst/README index 74482b88a..86ec57aae 100644 --- a/scst/README +++ b/scst/README @@ -1134,11 +1134,12 @@ SCST device and SCST target. An initiator however queries ALUA settings by sending an appropriate SCSI command to a specific LUN of an SCST target. Each such LUN maps uniquely to an SCST device. For hardware SCST target drivers, e.g. ib_srpt, there is a one-to-one correspondence between SCST target and -SCSI target port. With other SCST targets, e.g. iSCSI-SCST, the only -relationship between SCST targets and SCSI target ports is that all SCST -targets defined on a system are visible via all SCSI target ports. Hence for -target drivers like iSCSI-SCST configuring ALUA in SCST only makes sense in a -setup involving more than one system, e.g. a H.A. setup. +SCSI target port. With other SCST targets, e.g. iSCSI-SCST, by default the +only relationship between SCST targets and SCSI target ports is that all SCST +targets defined on a system are visible via all SCSI target ports. See also +the iSCSI-SCST documentation about the allowed_portal attribute for +information about how to associate iSCSI targets with a single physical +interface. Notes: - In a H.A. setup it is the responsibility of the user to synchronize ALUA @@ -1328,8 +1329,12 @@ Initiator Support ................. On Linux systems implicit ALUA support is provided by the scsi_dh_alua driver -of the device mapper. Information about how to configure the device mapper and -the scsi_dh_alua driver can be found in the manual of your Linux distribution. +of the device mapper. You will have to modify at least the following in +/etc/multipath.conf: +* path_checker scsi_dh_alua +* prio_callout "/sbin/mpath_prio_alua /dev/%n" +More information about how to configure the device mapper and the scsi_dh_alua +driver can be found in the manual of your Linux distribution. Windows initiator systems support ALUA from Windows Server 2008 on. For more information, see also: