From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willy Tarreau Subject: Re: What's the NFS OOM problem? Date: Thu, 10 Aug 2006 06:57:11 +0200 Message-ID: <20060810045711.GI8776@1wt.eu> References: <4ae3c140608081524u4666fb7x741734908c35cfe6@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel , linux-fsdevel@vger.kernel.org Return-path: Received: from 1wt.eu ([62.212.114.60]:47373 "EHLO 1wt.eu") by vger.kernel.org with ESMTP id S1161034AbWHJFOI (ORCPT ); Thu, 10 Aug 2006 01:14:08 -0400 To: Xin Zhao Content-Disposition: inline In-Reply-To: <4ae3c140608081524u4666fb7x741734908c35cfe6@mail.gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, Aug 08, 2006 at 06:24:47PM -0400, Xin Zhao wrote: > I often heard of the OOM probelm in NFS, but don't know what it is. > Now I am developing a NFS based system and found my system memory > (server side) is used too fast. I checked the code but didn't find > memory leaking. So I suspect I run into OOM issue. I simply think that you're cache is filling while your clients access a lot of files. That's expected. You might also get quite a bunch of dentries cached which will not be accounted for in meminfo. Check /proc/meminfo for the cache+buffer size, and check /proc/slabinfo for the number of dentries. The usual way to ensure this is only cache is to allocate a large amount of memory (let's say all the system RAM provided that everything can get swapped), then free it. You'll see a lot of free memory after that. > Can someone help me and give me a brief description on OOM issue? I don't know about any OOM issue related to NFS. At most it might happen on the client (eg: stating firefox from an NFS root) which might not have enough memory for new network buffers, but I don't even know if it's possible at all. Regards, Willy