From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [ofa-general][PATCH 3/4] SRP fail-over faster Date: Thu, 15 Oct 2009 15:35:12 -0600 Message-ID: <20091015213512.GW5191@obsidianresearch.com> References: <4AD3B453.3030109@mellanox.com> <4AD63681.6080901@mellanox.com> <4AD63DB1.3060906@mellanox.com> <1255570760.13845.4.camel@obelisk.thedillows.org> <4AD74C88.8030604@mellanox.com> <1255634715.29829.9.camel@lap75545.ornl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1255634715.29829.9.camel-FqX9LgGZnHWDB2HL1qBt2PIbXMQ5te18@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Dillow Cc: Vu Pham , Roland Dreier , Linux RDMA list List-Id: linux-rdma@vger.kernel.org On Thu, Oct 15, 2009 at 03:25:15PM -0400, David Dillow wrote: > On Thu, 2009-10-15 at 09:23 -0700, Vu Pham wrote: > > David Dillow wrote: > > > And if I want to disable this completely? > > > > > > > Unless these patches are bad and affect the stability of the driver, why > > do you want to disable it? If you don't use multipath/device-mapper and > > use /dev/sd**, everything will be same > > I use multipath with ALUA, and I don't mind if the link flaps a bit. 60 > seconds is near my SCSI timeout of 77 seconds, so it doesn't buy me > much. I'd rather multipath be delivering traffic to the backup path than > sitting on its thumbs for 60 seconds doing nothing. I've been left with a similar impression for several multipath things I've seen in the past. True active/active multipath setups should have a shorter timeout - there is no penalty for directing more traffic to the 2nd path (the paths should be load balancing existing traffic in the standard case anyhow). An active/passive configuration might be different... Certainly an enforced lower limit in the kernel is silly, and a per-device setting does make some sense. Jason -- 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