From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hughes Subject: Re: MD performance options: More =?windows-1252?Q?CPU=92s_or_?= =?windows-1252?Q?more_Hz=92s=3F?= Date: Mon, 09 Nov 2009 18:37:16 +0100 Message-ID: <4AF8534C.3030304@Calva.COM> References: <66781b10911040149q165edf1s94a86f179f9af9fc@mail.gmail.com> <4AF18A39.6010404@tmr.com> <4AF19216.30300@Calva.COM> <4AF8505D.9060007@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4AF8505D.9060007@tmr.com> Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: mark delfman , Linux RAID Mailing List List-Id: linux-raid.ids Bill Davidsen wrote: > John Hughes wrote: >> An external journal can be a huge win for ext3 if you are doing lots >> of file creates/deletes. (Striped raid, i.e. >> raid0/raid5/raid6/raid10 doesn't help the journal much as it is used >> sequentially. In my tests putting the journal on a raid1 and the >> rest of the fs on a raid10 makes things go much faster. If you have >> enough disks of course :-)) > > You might try mounting with data=journal and see what performance you > get with small reads and writes. Might surprise you. I hadn't thought > of using raid1 (or raid0 if speed is more important than survival), > but I have been playing with using SSD just for the journal. As you > say, when you do lots of creates or deletes it makes a big difference. Yup, data=journal will be in the next tests I do.