I am running postfix on RH machine. decided to upgrade one of my machines from 7.1 to 7.2 - performance drop of 75 percent !!!!! moved back to ext2(remount partition as ext2) - performance is back. on the 7.1 upgraded to ext3 (only the disks), rebooted - performance drop of 70 percent... used a 2.4.17 kernel compiled by myself - a little faster then the last RH kernel, but still runs at third of the best speed !!! mountext all partitions as ext3 except /var (postfix queue is there) - performance is good. any comments, suggestions ? i don't thiink it's an acceptable compromise to loose 75% performance to gain better recoverablility, considering the stability of linux. Alex
On Feb 10, 2002 01:18 +0200, Alex Kramarov wrote:> I am running postfix on RH machine. decided to upgrade one of my machines > from 7.1 to 7.2 - performance drop of 75 percent !!!!! > > moved back to ext2(remount partition as ext2) - performance is back. > > mountext all partitions as ext3 except /var (postfix queue is there) - > performance is good.You should mount your mail spool with "data=journal". While this may seem contradictory (forcing journaling for the data in addition to the metadata), it will likely improve the performance for sync I/O loads like mail servers because it can do all of the I/O to the journal without any seek or sync overhead while the mail is arriving. Eventually the journal will flush the data to the disk, but this can be done async because it is already safe in the journal. Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/
On Sun, Feb 10, 2002 at 01:18:14AM +0200, Alex Kramarov wrote:> I am running postfix on RH machine. decided to upgrade one of my > machines from 7.1 to 7.2 - performance drop of 75 percent !!!!! > > moved back to ext2(remount partition as ext2) - performance is back. > > on the 7.1 upgraded to ext3 (only the disks), rebooted - performance > drop of 70 percent... > > used a 2.4.17 kernel compiled by myself - a little faster then the > last RH kernel, but still runs at third of the best speed !!! > > mountext all partitions as ext3 except /var (postfix queue is there) > - performance is good.* mount /var/spool/postfix in data=journal mode * mount /var/log in data=ordered mode * chattr -R -S /var/spool/postfix -- Ralf Hildebrandt (Im Auftrag des Referat V A) Ralf.Hildebrandt@charite.de Charite Campus Virchow-Klinikum Tel. +49 (0)30-450 570-155 Referat V A - Kommunikationsnetze - Fax. +49 (0)30-450 570-916 (S)he's out buying some caffeine.
> You should mount your mail spool with "data=journal". While this may > seem contradictory (forcing journaling for the data in addition to the > metadata), it will likely improve the performance for sync I/O loads > like mail servers because it can do all of the I/O to the journal without > any seek or sync overhead while the mail is arriving. Eventually the > journal will flush the data to the disk, but this can be done async > because it is already safe in the journal.the proposed solution has (more or less) no effect. i hope i have done it right - here is the autput of "mount" for the var partition - is this the correct setting ? /dev/sda6 on /var type ext3 (rw,data=journal) Alex.