On Thu, Jul 9, 2009 at 7:29 PM, Greg Stark<gsstark@xxxxxxx> wrote: > On Fri, Jul 10, 2009 at 1:28 AM, Scott Marlowe<scott.marlowe@xxxxxxxxx> 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. > > > Fwiw the main disadvantage of software raid is NOT speed -- Linux > software RAID is very fast. Aside from raid-5 where it lets you > offload the parity calculation there really isn't much speed benefit > to hardware 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. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
