From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick - South Valley Internet Subject: Re: Creating a Load Balanced E-mail Server with NFS mounts with CentOS - how to optimize for performance? Date: Sat, 14 Jul 2007 16:38:09 -0700 Message-ID: <46995E61.4050503@garlic.com> References: <4698100A.1070702@garlic.com> <1184427086.7115.13.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net To: Trond Myklebust Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1I9rBf-00061f-WB for nfs@lists.sourceforge.net; Sat, 14 Jul 2007 16:38:08 -0700 Received: from sequoia.garlic.com ([216.139.0.84]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1I9rBj-0006nG-ID for nfs@lists.sourceforge.net; Sat, 14 Jul 2007 16:38:11 -0700 In-Reply-To: <1184427086.7115.13.camel@heimdal.trondhjem.org> List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net Trond Myklebust wrote: > On Fri, 2007-07-13 at 16:51 -0700, Patrick - South Valley Internet > wrote: > >> Hi all, >> >> I'm finishing up our new load balanced e-mail server which consists of >> two Dell dual cpu Opterons NFS mounting our 1.6TB RAID 5 server - all 3 >> machines run CentOS. I have VMWare server installed on both Dell >> Opterons which both machines run a CentOS LDAP server (uses 256mb RAM), >> and a CentOS Postfix server. I have noticed no performance loss running >> VMWare, as far as I can tell. The reason I mention this is because I've >> had experience in the past with other applications, such as >> Trixbox/Asterisk that require you to NOT run this on a VM due to issues >> with real time processing and such. Just want to make sure that this >> isn't the case for this scenerio (which I don't think, since I'm only >> experiencing issues on the NFS mounted directories) >> >> Anyhow, I can successfully mount the NFS from both Postfix VM's without >> a problem. I created a /vol/vol0/home directory on the NFS, and mount >> that to /home on both Postfix VM's. Doing a 'ls -l' in /home takes >> forever, sometimes longer than I wish (30+ seconds, sometimes longer). >> I read the NFS performance documentation on testing the read and write >> speeds and timing them, and I've come up with these: >> >> ##################### >> [root@somebox mnt]# time dd if=/dev/zero of=/home/testfile bs=16k >> count=16384 >> 16384+0 records in >> 16384+0 records out >> >> real 0m43.282s >> user 0m0.010s >> sys 0m2.043s >> >> >> >> [root@somebox mnt]# time dd if=/home/testfile of=/dev/null bs=16k >> 16384+0 records in >> 16384+0 records out >> >> real 0m22.943s >> user 0m0.016s >> sys 0m0.629s >> #################### >> >> >> I've tried to set different rsize and wsize (4096, 8192, 16384, and >> 32768), and it doesn't seem to be doing any different. I've checked the >> switch settings to make sure there weren't any inconsistencies and are >> set to 100xFD. >> >> >> >> My /etc/fstab looks like this: >> >> xxx.yyy.com:/vol/vol0/home /home nfs >> rw,hard,intr,rsize=32768,wsize=32768 0 0 >> xxx.yyy.com:/vol/vol0/spool-mail /spool-mail nfs >> rw,hard,intr,rsize=32768,wsize=32768 0 0 >> xxx.yyy.com:/vol/vol0/spool-xxx-mqueue /spool-mqueue >> nfs rw,hard,intr,rsize=32768,wsize=32768 0 0 >> >> >> I'm concerned because there will be a lot of activity on these servers, >> and I need this to be as fast as possible. >> >> Do I have my mountpoints defined properly? >> >> If I need to provide hardware descriptions of my machines, let me know >> and I will do a lspci. >> >> Thanks to everyone in advance. >> > > Three questions: > 1. What kind of network are you using for your VMWare installation? > If you are using NAT, I'd suggest trying a bridged network > instead. > 2. Are you using TCP or UDP? It is not clear from the above what > the default is on CentOS. I'd suggest explicitly selecting TCP. > 3. What kind of iptables setup do you have? > > Trond > > > > > > Thanks for the response. 1) I am using Bridged Network for the VMWare installation. 2) I'm not sure if I am using TCP or UDP - how do I check? 3) I do not have any iptables set up - should I? Thanks again for the response. Let me know if I need to provide anymore information. Patrick ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs