From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id CA7D27CBF for ; Tue, 30 Jul 2013 17:35:18 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id ACEB38F8033 for ; Tue, 30 Jul 2013 15:35:15 -0700 (PDT) Date: Wed, 31 Jul 2013 08:34:50 +1000 From: Dave Chinner Subject: Re: [xfs-masters] how to use fstrim? Message-ID: <20130730223450.GL13468@dastard> References: <51F2BD31.5060301@profihost.ag> <20130727015029.GT13468@dastard> <51F815EB.9040000@profihost.ag> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <51F815EB.9040000@profihost.ag> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Stefan Priebe Cc: "xfs-masters@oss.sgi.com" , "xfs@oss.sgi.com" On Tue, Jul 30, 2013 at 09:37:15PM +0200, Stefan Priebe wrote: > Am 27.07.2013 03:50, schrieb Dave Chinner: > >On Fri, Jul 26, 2013 at 08:17:21PM +0200, Stefan Priebe wrote: > >>Hi, > >> > >>what is the right way to use fstrim on top of XFS? just doing fstrim > >>-v -m 4194304 / > >> > >>results sometimes (might depend on disk i/o) to hanging tasks and > >>stack traces - fstrim needs > 5 min in these cases. > > > >It does indeed depend on disk IO. XFS walks all the free space and > >issues discards on it, so runtime is always O(freespace). And while > >it is walking an AG discarding the free space, it will hold the AG > >locked so that free space doesn't change. This can hang other > >operations for the length of time it takes to discard all the free > >space in the AG. > > IOWs, the behaviour of fstrim on XFS is entirely dependent on the > > speed of the block layer and hardware implementations of discards. > > Yes OK i understand that but is there any way to prevent getting the > whole server crash when I/O is too much? Sorry, what crash are you talking about? IO being slow because you ran fstrim isn't a crash.... > For example splitting whole disk or even AGs into subparts? Or set a > timeout for the fstrim command? You can split fstrim up into smaller sections yourself by using the range parameters. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs