From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Large single raid and XFS or two small ones and EXT3? Date: Mon, 26 Jun 2006 10:03:58 -0400 Message-ID: <449FE94E.9000307@tmr.com> References: <449AEB7C.6040108@cjx.com> <449BE381.6070000@cjx.com> <68c491a60606230746m5c1f0301g8e00fdd4f0e0739b@mail.gmail.com> <449C0505.8000601@tmr.com> <17564.52087.651968.635043@cse.unsw.edu.au> <449CF0D0.9080006@comcast.net> <449F22D7.2090604@tmr.com> <449F2D80.6080100@comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <449F2D80.6080100@comcast.net> Sender: linux-raid-owner@vger.kernel.org To: Adam Talbot Cc: Neil Brown , Francois Barre , linux-raid@vger.kernel.org List-Id: linux-raid.ids Adam Talbot wrote: >Not exactly sure how to tune for stripe size. >What would you advise? >-Adam > > See the -R option of mke2fs. I don't have a number for the performance impact of this, but I bet someone else on the list will. Depending on what posts you read, reports range from "measurable" to "significant," without quantifying. Note, next month I will set up either a 2x750 RAID-1 or 4x250 RAID-5 array, and if I got RAID-5 I will have the chance to run some metrics before putting the hardware into production service. I'll report on the -R option if I have any data. > >Bill Davidsen wrote: > > >>winspeareAdam Talbot wrote: >> >> >> >>>OK, this topic I relay need to get in on. >>>I have spent the last few week bench marking my new 1.2TB, 6 disk, RAID6 >>>array. I wanted real numbers, not "This FS is faster because..." I have >>>moved over 100TB of data on my new array running the bench mark >>>testing. I have yet to have any major problems with ReiserFS, EXT2/3, >>>JFS, or XFS. I have done extensive testing on all, including just >>>trying to break the file system with billions of 1k files, or a 1TB >>>file. Was able to cause some problems with EXT3 and RiserFS with the 1KB >>>and 1TB tests, respectively. but both were fixed with a fsck. My basic >>>test is to move all data from my old server to my new server >>>(whitequeen2) and clock the transfer time. Whitequeen2 has very little >>>storage. The NAS's 1.2TB of storage is attached via iSCSI and a cross >>>over cable to the back of whitequeen2. The data is 100GB of user's >>>files(1KB~2MB), 50GB of MP3's (1MB~5MB) and the rest is movies and >>>system backups 600MB~2GB. Here is a copy of my current data sheet, >>>including specs on the servers and copy times, my numbers are not >>>perfect, but they should give you a clue about speeds... XFS wins. >>> >>> >>> >>> >>In many (most?) cases I'm a lot more concerned about filesystem >>stability than performance. That is, I want the fastest >>filesystem. With ext2 and ext3 I've run multiple multi-TB machines >>spread over four time zones, and not had a f/s problem updating ~1TB/day. >> >> >> >>Did you tune the extN filesystems to the stripe size of the raid? >> >> >> -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979