General Performance Guidelines

When you design your storage configuration, consider the following performance guidelines:

• Striping generally has the best performance, but striping offers no data redundancy. For write-intensive applications, RAID-1 volumes generally have better performance than RAID-5 volumes.

• RAID-1 and RAID-5 volumes both increase data availability, but both types of volumes generally have lower performance for write operations. Mirroring does improve random read performance.

• RAID-5 volumes have a lower hardware cost than RAID-1 volumes, while RAID-0 volumes have no additional hardware cost.

• Both stripes and RAID-5 volumes distribute data across multiple disk drives and help balance the I/O load.

• Identify the most frequently accessed data, and increase access bandwidth to that data with mirroring or striping.

• Use available performance monitoring capabilities and generic tools such as the iostat command to identify the most frequently accessed data. Once identified, the access bandwidth to this data can be increased using striping, RAID-1 volumes or RAID-5 volumes.

• The performance of soft partitions can degrade when the soft partition size is changed multiple times.

• RAID-5 volume performance is lower than stripe performance for write operations. This performance penalty results from the multiple I/O operations required to calculate and store the RAID-5 volume parity.

• For raw random I/O reads, the stripe and the RAID-5 volume are comparable. Both the stripe and RAID-5 volumes split the data across multiple disks. RAID-5 volume parity calculations are not a factor in reads except after a slice failure.

• For raw random I/O writes, the stripe is superior to RAID-5 volumes.

For configuration guidelines specific to Solaris Volume Manager, see Solaris Volume Manager Configuration Guidelines.