From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCH 00/19, v5] Make ib_srp better suited for H.A. purposes Date: Tue, 13 Nov 2012 09:41:57 +0100 Message-ID: <50A207D5.6060207@acm.org> References: <508A85BB.1000505@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Or Gerlitz Cc: "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , David Dillow , Roland Dreier List-Id: linux-rdma@vger.kernel.org On 11/12/12 23:36, Or Gerlitz wrote: > Bart Van Assche wrote: >> This patch series makes the ib_srp driver better suited for use in a H.A. setup because: >> - multipathd is notified faster about transport layer failures. >> - Transport layer failures reliably result in SCSI host removal. >> - Switchover can be triggered explicitly by deleting an initiator device. >> - Disconnecting from a target without unloading ib_srp is now possible. > > Can you describe few use cases, HA tests which don't pass w.o these > patches and do pass or react better with them? This patch series reduces path failover time significantly. Instead of having to wait until the SCSI error handler has finished recovery, multipathd switches paths as soon as fast_fail_tmo has elapsed. Also, SCSI hosts that correspond to failed paths are removed. With the upstream SRP initiator and when triggering path failover repeatedly after some time hundreds of obsolete SCSI hosts are present. >> Changes since v2: > [...] >> - Dropped the patches for integration with multipathd. > can you explain this please? are these non SRP patches which we > submitted/accepted > through another maintainer? can you point on the upstream commits? With that comment I was referring to the dev_loss_tmo and fast_io_fail_tmo sysfs variables that had been dropped in v2 of this patch set but that have been reintroduced in v3 of this patch set. If these parameters have been set in /etc/multipath.conf then multipathd passes these on to the block driver (ib_srp in this case), at least the block driver provides the dev_loss_tmo and fast_io_fail_tmo sysfs attributes. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html