Re: Database storage

> On Thu, Jul 9, 2009 at 7:29 PM, Greg Stark<gsstark(at)mit(dot)edu> wrote:
>> On Fri, Jul 10, 2009 at 1:28 AM, Scott Marlowe<scott(dot)marlowe(at)gmail(dot)com> wrote:
>>>
>>> $750 is about what a decent RAID controller would cost you, but again
>>> it's likely that given your bulk import scenario,  you're probably ok
>>> without one.  In this instance, you're probably best off with software
>>> RAID than a cheap RAID card which will cost extra and probably be
>>> slower than linux software RAID.
...
>> The main advantage of hardware raid is the error handling. When you
>> get low level errors or pull a drive a lot of consumer level
>> controllers and their drivers don't respond very well and have long
>> timeouts or keep retrying tragically unaware that the software raid
>> would be able to handle recoverying. A good server-class RAID
>> controller should handle those situations without breaking a sweat.

> Definitely a big plus of a quality HW controller, and one of the
> reasons I don't scrimp on the HW controllers I put in our 24/7
> servers.  OTOH, if you can afford a bit of downtime to handle
> failures, linux software RAID works pretty well, and since quad core
> CPUs are now pretty much the standard, it's ok if parity calculation
> uses up a bit of one core for lower performing servers like the
> reporting server the OP was talking about.

The database server is a quad core machine, so it sounds as though
software RAID should work fine for the present setup. However, it
sounds as though I should put some money into a hardware RAID
controller if the database becomes more active. I had assumed RAID-5
would be fine, but please let me know if there is another RAID level
more appropriate for this implementation. Thanks for the valuable
insight!