From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id j0OHrCO26762 for ; Mon, 24 Jan 2005 12:53:12 -0500 Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.206]) by mx3.redhat.com (8.12.11/8.12.11) with ESMTP id j0OHr6UB008734 for ; Mon, 24 Jan 2005 12:53:07 -0500 Received: by wproxy.gmail.com with SMTP id 67so179707wri for ; Mon, 24 Jan 2005 09:53:01 -0800 (PST) Message-ID: <87f94c37050124095332866424@mail.gmail.com> Date: Mon, 24 Jan 2005 12:53:01 -0500 From: Greg Freemyer Subject: Re: [linux-lvm] Why the dramatic increase in filesystem performance when usingxfs???? In-Reply-To: <20050124113204.B1604791@wobbly.melbourne.sgi.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit References: <1106304669.3943.14.camel@grma-lap> <87f94c3705012108241f812e0e@mail.gmail.com> <20050124113204.B1604791@wobbly.melbourne.sgi.com> Reply-To: Greg Freemyer , LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: Nathan Scott Cc: Gary.Mansell@ricardo.com, LVM general discussion and development On Mon, 24 Jan 2005 11:32:05 +1100, Nathan Scott wrote: > On Fri, Jan 21, 2005 at 11:24:29AM -0500, Greg Freemyer wrote: > > Specifically, I would not recommend XFS for the core filesystems. i.e > > /, /var, /usr, etc. A lot of debug tools still don't support XFS and > > XFS brings no value to the party. > > Which debug tools are you referring to there? I've found XFS > to be an excellent "core" filesystem, but I may be biased. :) > > cheers. > > -- > Nathan > Nathan, You biased, never. One issue I recently saw (last summer) was SUSE 9.1 QC testing failed to test for XFS capability. That resulted in a full distro release with no XFS support. Work arounds were immediately provided, but none of the CDs that came with the distro allowed you to boot from the CD and access a XFS filesystem. For the test system I was upgrading it was not too bad because XFS was purely on my data partitions. (ie. I upgraded the OS and core filesystems, used YOU to get the online updates, then accessed my fliesystems.) If I had my core filesystems under XFS, I'm not sure what the fix would have been. Further booting SUSE 9.1 into rescue mode created an environment that could not mount any of the XFS partitions. Also, last springs release of Knoppix may have XFS support (I don't know), but it is so unreliable, I still use the 2-year old version. No XFS support there. Another problem I've recently read about is that XFS on / and software RAID5 are incompatible. (I have not tried this.) Basically, I just don't think the various distros get enough testing of XFS to use it for core filesystems and if you need to use distros/repair CDs from 12+ months ago you also have problems with XFS. Now a question for you: I have not read a status update of XFS/snapshots/2.6.x. Can you tell me if this is expected to work or not? (Obviously, I don't care about '/'). This issue and my percieved lack of confidence in its suppport is one of the prime reasons my production fileservers are still running 2.4 kernels. If you think it is working, I'm ready to load SUSE 9.2 onto one of my test platforms and test the above. It is easy enough to compile a 2.6.10 vanilla kernel if that is likely to be better than the 2.6.8+ kernel that SUSE distributes. Thanks Greg -- Greg Freemyer