Hi list, I am having some strange performance issues with ext3 and I am hoping to get some advice/hints on how to make this better. First some background on the setup. We have a RAID 5 array 10+1+1 with one LUN. That is 10 SATA drives one parity drive and one dedicated spare. The LUN is about 6.5TB. Using a 2Gbit/sec fiber channel card I can do some dd writes to the raw device and get speeds close to 200Mbytes/sec which is more or less the max the card can do. Next I create an xfs file system on the LUN and do a dd to xfs and get speeds close to 150Mbytes/sec. I want to use ext3 not xfs so next I put ext3 on the lun. Now when I do the dd to the ext3 lun I get 25-50Mbytes/sec depending on whether I have the Raid controller cache turned on or off. Getting 50MBytes/sec with the raid controller cache turned off. I know that ext3 should perform better so I must be doing something wrong. Here is my mkfs.ext3 mkfs.ext3 -b4096 -Tlagefile4 /dev/dm-0 Thanks in advanced for any help on this. Rene -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://listman.redhat.com/archives/ext3-users/attachments/20070808/ae7020b2/attachment.htm>
Hi Rene, You should try to add the "-E stride=X" option to the mkfs command line. Where X is expalined in the man page. This will basically map ext3 "blocks" on the RAID stripe size. Ionel -------- Message d'origine-------- De: ext3-users-bounces at redhat.com de la part de Rene Salmon Date: mer. 08/08/2007 22:21 ?: ext3-users at redhat.com Objet : Poor ext3 performance on RAID array Hi list, I am having some strange performance issues with ext3 and I am hoping to get some advice/hints on how to make this better. First some background on the setup. We have a RAID 5 array 10+1+1 with one LUN. That is 10 SATA drives one parity drive and one dedicated spare. The LUN is about 6.5TB. Using a 2Gbit/sec fiber channel card I can do some dd writes to the raw device and get speeds close to 200Mbytes/sec which is more or less the max the card can do. Next I create an xfs file system on the LUN and do a dd to xfs and get speeds close to 150Mbytes/sec. I want to use ext3 not xfs so next I put ext3 on the lun. Now when I do the dd to the ext3 lun I get 25-50Mbytes/sec depending on whether I have the Raid controller cache turned on or off. Getting 50MBytes/sec with the raid controller cache turned off. I know that ext3 should perform better so I must be doing something wrong. Here is my mkfs.ext3 mkfs.ext3 -b4096 -Tlagefile4 /dev/dm-0 Thanks in advanced for any help on this. Rene -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://listman.redhat.com/archives/ext3-users/attachments/20070808/90c9b82d/attachment.htm>
On Aug 08, 2007 15:21 -0500, Rene Salmon wrote:> I am having some strange performance issues with ext3 and I am hoping to > get some advice/hints on how to make this better. First some background > on the setup. > > We have a RAID 5 array 10+1+1 with one LUN. That is 10 SATA drives one > parity drive and one dedicated spare. The LUN is about 6.5TB. > > Using a 2Gbit/sec fiber channel card I can do some dd writes to the raw > device and get speeds close to 200Mbytes/sec which is more or less the > max the card can do. > > Next I create an xfs file system on the LUN and do a dd to xfs and get > speeds close to 150Mbytes/sec. > > I want to use ext3 not xfs so next I put ext3 on the lun. Now when I do > the dd to the ext3 lun I get 25-50Mbytes/sec depending on whether I have > the Raid controller cache turned on or off. Getting 50MBytes/sec with > the raid controller cache turned off. > > I know that ext3 should perform better so I must be doing something > wrong. Here is my mkfs.ext3 > > mkfs.ext3 -b4096 -Tlagefile4 /dev/dm-0You could also try out ext4, that's where the real performance improvements are... Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.