I have been seeing a lot of people using 1.5Tb and greater hard drives lately, and find myself getting pretty uncomfortable about them using plain old RAID5 for 12-16 1.5Tb drives.

With the failure rate of SATA drives not being something to smile about, and the length of time required to rebuild arrays of this size, I am strongly inclined to recommend RAID6 to users. These days the performance hit is not that great (almost negligible) but the safety factor of being able to survive 2 simultaneous hard drive failures, or a second drive failure during a single drive failure rebuild, is, I think, worth it.

However … as drives get larger, the capacity hit of RAID6 becomes greater. “I don’t want to lose 1.5Tb capacity” is what I often hear from people when I suggest RAID6. Simply put, the increased size of the drive means increased lost capacity when moving from RAID5 to RAID6. While I think the simple solution is to just purchase more drives, it seems not everyone has my deep pockets (unsurprising as that may be in these economic times).

But … I’d strongly urge people to consider RAID6 when using large SATA hard drives to cover themselves (and their data) - and be damned with the capacity issues. I’d rather keep 14×1.5Tb data than lose 15×1.5Tb data.

Food for thought.

Ciao
Neil

This entry was posted on Thursday, October 29th, 2009 and is filed under General, Storage Applications, Platforms, Storage Interconnects & RAID, Storage Management, Application Environments, Advisor - Neil. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.