Why are array architectures so old? — StorageMojo
25 years ago I was working on DEC’s earliest RAID array. When I look at today’s “high-end” arrays, it’s shocking how little architectural change the big iron arrays have embraced.
The industry is ripe for disruption, only part of which is coming from cloud vendors. 21st century problems demand 21st century architectures.
Here’s a list of the obsolete technologies still embraced by most large arrays.
RAID. After it turned out that the governing assumption behind RAID was not accurate – non-correlated failures – and as drive sizes increased, RAID data losses and rebuild times are both too high. Rebuild times have rendered traditional RAID 5 and 6 enterprise arrays functionally obsolete.
Active/active controllers. CPU cycles used to be costly. Now they’re cheap. If performance and availability are paramount, triple controllers – active/active/active – or better are the way to go.
Low density drive enclosures. Why do we need to install drives at a moment’s notice? RAID. Drive failures in a stripe – even with RAID 6 – threaten data integrity due to failure correlation and silent data corruption. Get rid of RAID in favor of modern redundancy techniques and drive replacements can be handled by calm, awake people.
Fiber channel drives. With the rise of much faster SSDs with dual SAS connectors there is little reason for fiber channel drives. Dump ‘em.