On 14 Jun 2012, at 15:22, "Fernando Frediani (Qube)" <fernando.frediani at qubenet.net> wrote: > Well, as far as I know the amount of IOPS you can get from a RAID 5/6 is the same that you get from a single disk. The write can not be acknowledged until it is written to all the data and parity disks. It can exceed that with battery back-up on the controller. With battery back-up, writes are often faster than reads (in all of IOPS, latency and throughput), at least until you hit the cache size limit. Sustained writes will not get such good performance because of the limit you mention, but random writes can still do pretty well, YMMV. If you want to scale writes properly, you need some variant of RAID-10. I've got one server with RAID-10 across 6 SSDs, works well. Marcus -- Marcus Bointon Synchromedia Limited: Creators of http://www.smartmessages.net/ UK info at hand CRM solutions marcus at synchromedia.co.uk | http://www.synchromedia.co.uk/
