Oracle Chooses XServe RAID

Apple's Xserve RAIDIt looks like Oracle has decideded to adopt Apple’s XServe RAID as a low-cost storage solution

Based on our own experience with Apple technology, Xserve RAID is a great match for applications running Oracle.

With the appetite of one to two petabytes annually Oracle is of course looking to control costs and the SATA-based Xserve RAID combines value, capacity, performance and availability. The current top configuration offers 7000GB on dual RAID controllers with redundant power and cooling for a mere $12999. Sure that’s the price of a small car, but it works out to only $1.86/GB for some serous industry-level storage.

Thanks to Zach for sending this on to me.

apple, oracle, xserve, raid, xserve raid, storage, disk, hard drive

RAID 5 and Oracle Databases

While researching the effect of RAID 5 disk configuration on Oracle databases I came accrost more than I thought I expected on the topic.

With disk as cheap as it is today there is no reason to ever use RAID 5 on an Oracle database. Even for a database which sees only a moderate amount of updates the performance loss incurred by using RAID 5 is too high. RAID 1 or some combination of RAID 1 and RAID 0 should be used when high availability is required. Database 10g users should also consider allowing Oracle’s new Automatic Storage Management to handle redundancy on un-mirrored disks (or even raw partitions.)

But don’t take my word for it. Here are some opinions from some notable Oracle administrators:

Oracle Database RAID 5
Mark Rittman

No RAID5. Use RAW whenever possible and consider RAID10 or 0+1. RAID 5 can severely affect performance on highly updated databases.

Oracle Database Administration: The Essential Reference
David Kreines & Brian Laskey

RAID-5 is, in fact, very powerful and inexpensive. It is also a technology to be avoided in most cases when configuring your Oracle database! This may seem a harsh statement, but the reality is that although RAID-5 provides good levels of data protection at a low monetary cost, this comes at a very high cost for disk I/O. In particular, write operations on RAID-5 arrays can be orders of magnitude slower than the same operations on a single disk.

Oracle and RAID usage
Mike Ault

Use RAID10 when possible, RAID5 if it is not. Size the array based on IO needs first, then storage capacity and you can’t go wrong.

Disk Management for Oracle
Donald Burleson

Oracle recommends using (SAME) Stripe And Mirror Everywhere (a.k.a., RAID 1+0) for all systems that experience significant updates. This is because of the update penalty with RAID 5 architectures.

Using RAID 5 for a high-update Oracle system can be disastrous to performance, yet many disk vendors continue to push RAID 5 as a viable solution for highly updated systems.

RAID 5 is not recommended for high-update Oracle systems. The performance penalty from the parity checking will clobber Oracle performance.

If you’re still not convinced check out This site is committed to the Battle Against Any Raid Five (or four or free, uh, three.) The site has links to several more articles exposing the perils of RAID 5.

oracle, rdbms, dba, systems administration, sysadmin, raid, raid 5