Managing IMAP

I/O Subsystem Tuning

Disk storage requirements can grow by as much as 100% per year. The more storage grows, the more important it becomes to provide reliable access to the data. To ensure both economical and reliable access to data, it’s important to consider both scalability and high availability. The section discusses factors to consider when you select a disk subsystem for your IMAP server.

Special I/O Considerations for Cyrus and UW Systems

On Cyrus servers, disk configuration is the most critical factor in system performance. The Cyrus server is I/O bound, and if the disk configuration is not tuned, the system will spend too much time in the I/O wait state. The general idea is to have the logging partition, mailstore, mailboxes file, and mail queue partition as spread out as possible over disks and controllers. Read the Performance Notes section of the Cyrus installation guide for performance tuning guidelines.

On UW servers, disk configuration is the most critical factor in system performance. The UW server is I/O bound, and if the disk configuration is not tuned, the system will spend too much time in the I/O wait state. The general idea is to have the logging partition, mailbox files, and mail queue partition as spread out as possible over disks and controllers. A secondary consideration with UW servers is memory; when in doubt, put more RAM on your UW server, but only after tuning your disk configuration first.

Disk Interface

Integrated Drive Electronics (IDE)

Avoid ...