-------- Original Message -------- Subject: Storage Sizing: IOPS per mailbox From: ram <ram@xxxxxxxxxxxxx> To: info-cyrus <info-cyrus@xxxxxxxxxxxxxxxxxxxx> Date: Friday, January 02, 2009 10:40:17 PM > When sizing a storage device for a large cyrus server, the typical > question asked by storage vendors is what is the IOPS required per > mailbox > M$$ Exchange has this concept of IOPS. and they suggest 1.5 IOPS per > mailbox ( heavy users ) > > If I use postfix and cyrus , on my imap server ( pure IMAP server .. All > spam filtering , outgoing mails , authentication etc happens on > different servers ) > > > If the storage is used only for imap storage , what is the typical > "IOPS" requirement per user > We will probably assume 30-50 mails a day of average 100k , and an email > client checking for new mail every 5minutes > > > In my experience I would estimate 0.1 IOPS per user for heavy users (thousands of emails per day, checked every few minutes) and 0.01 IOPS per user for typical ISP accounts (under a dozen emails, checked a few times daily). Our systems use MySQL for authentication and account verification and primarily skiplist databases within Cyrus. These figures may be on the safe side as none of our systems do just postfix/imap. --Blake ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
