Matt schrieb: > I have an email server running Exim, Dovecot, Spamassassin, Clam, etc. > on Centos 4.x 32bit. On occasion I have disk I/O problems. Its > handling several domains and alot of email. Its currently on a single > SATA drive. I am thinking of moving too 3 drives with RAID 1 for > redundancy. RAID 1 will help me on reads but do nothing on writes as > I understand. I am thinking the majority of my I/O is read though > not? I imagine quotta checks and all that being done and everytime a > user checks there email every message in the inbox must be read. > > I guess I am asking if RAID 1 will help my I/O problem much? > > [root at server ~]# w > 12:04:02 up 2:01, 1 user, load average: 7.02, 7.47, 11.84 > USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT > root pts/0 208.92.169.4.ppp 11:25 0.00s 0.02s 0.00s w > [root at server ~]# vmstat > procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- > r b swpd free buff cache si so bi bo in cs us sy id wa > 0 2 0 1558496 456916 1087224 0 0 198 749 795 537 18 4 27 50 > > The above is when its running pretty good. > > Matt > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > How many concurrent users? If you stay with SATA, you will probably have to increase the amount of disks in you storage-array (depending on the number of users). A SATA disk does only 80 I/Os per second or so - and clamav+spamassassin alone will consume a lot of these. Try to put their working-directories on a swap-backed tmpfs. cheers, Rainer