From: Alan Powell Subject: RE: iostat wkB/s numbers during testing Date: Fri, 14 Feb 2003 09:35:24 -0800 (PST) Sender: nfs-admin@lists.sourceforge.net Message-ID: <20030214173524.67891.qmail@web12205.mail.yahoo.com> References: <6440EA1A6AA1D5118C6900902745938E07D552E3@black.eng.netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Return-path: Received: from web12205.mail.yahoo.com ([216.136.173.89]) by sc8-sf-list1.sourceforge.net with smtp (Exim 3.31-VA-mm2 #1 (Debian)) id 18jjkD-00030d-00 for ; Fri, 14 Feb 2003 09:35:25 -0800 To: "Lever, Charles" , Paul Heinlein In-Reply-To: <6440EA1A6AA1D5118C6900902745938E07D552E3@black.eng.netapp.com> Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: If you do lots of writes, it's especially important that you enable the RAID controllers write-back cache (if you're concerned about data loss in case of power failure, you can get battery backup for most cards for a little more than $100). Also, ideally you'd try to keep write-intensive stuff on a RAID-1 partition, and the rest on RAID-5, b/c RAID-5 is _very_ inefficient at writes. If you have 6 drives, why don't you set 2 of them aside for RAID-1 and the most write-intensive files? --- "Lever, Charles" wrote: > hi paul- > > you can check the list archives for more > information, > but the experiences on this list have been that RAID > 5 is generally not a hi-performance back-end > solution > for Linux NFS servers. > > i believe the problem is that NFS servers generate > lots > of small writes, and that's something RAID 5 is not > very good at. > > i can't answer your specific question about the > numbers > you posted. maybe someone else? > > > -----Original Message----- > > From: Paul Heinlein [mailto:heinlein@cse.ogi.edu] > > Sent: Friday, February 14, 2003 10:32 AM > > To: nfs@lists.sourceforge.net > > Subject: [NFS] iostat wkB/s numbers during testing > > > > > > I'm using a dual P-III Compaq DL380 running Red > Hat 8.0 to > > host a new ATABoy RAID array purchased from > Nexsan. It's > > connected to our switch via a gig/fiber card based > on the > > Intel 82542 chipset. > > > > The service stack (for lack of a better phrase) is > > > > * ATABoy2 -- six-drive RAID-5 array that presents > itself to the host > > as a single SCSI device (no multiple > LUNs) > > * LVM -- 1.0.3, one PV, one VG, one LV (so far > :-) > > * XFS -- 1.2pre5 > > * NFS -- v2/v3, UDP only, 80 nfsd threads > > * Samba -- 2.2.7 > > > > Last night, I set up six NFS clients and one > Linux/smbfs > > client to run > > iozone against the nfs mount/samba share. > > > > I was keeping track of stats using iostat -x on > the server. > > My typical wkB/s numbers hovered in the 15000 to > 19000 range. > > Is that sort of result set consistent with what > any of you > > have seen for Linux-hosted > > NFS RAID exports? > > > > --Paul Heinlein > > > > > > > > > ------------------------------------------------------- > > This SF.NET email is sponsored by: FREE SSL Guide > from > > Thawte are you planning your Web Server Security? > Click here > > to get a FREE Thawte SSL guide and find the > answers to all > > your SSL security issues. > > http://ads.sourceforge.net/cgi-> > bin/redirect.pl?thaw0026en > > > > > > _______________________________________________ > > NFS maillist - NFS@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/n> fs > > > > > ------------------------------------------------------- > This SF.NET email is sponsored by: FREE SSL Guide > from Thawte > are you planning your Web Server Security? Click > here to get a FREE > Thawte SSL guide and find the answers to all your > SSL security issues. > http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0026en > _______________________________________________ > NFS maillist - NFS@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nfs __________________________________________________ Do you Yahoo!? Yahoo! Shopping - Send Flowers for Valentine's Day http://shopping.yahoo.com ------------------------------------------------------- This SF.NET email is sponsored by: FREE SSL Guide from Thawte are you planning your Web Server Security? Click here to get a FREE Thawte SSL guide and find the answers to all your SSL security issues. http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0026en _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs