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@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@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