Most of the things in this email, from me are a personal opinoin, but I do spend a fair bit of time with these sort of things, these days.
Therese Trudeau wrote:
3Ware 8000-series cards are probably the most compatible going back at least 3 years. 9000-series cards are faster/better and CentOS 5.1 should have full support for them.
I would'nt bother with a 3ware 8000 or a 3ware 9000 card these days, if you really do want to get 3ware, get atleast a 9650. And anything less than a 9550 should be considered only if you get a really good deal off ebay. And remember that battery backup unit.
For me, in SATA RAID cards it's 3ware or nothing. Been using them for more than 8 years now.
I used to think the same for a long time, till I started using Areca raid cards. Now, I rate 3ware well behind Areca on performance, reliability and ease of use. If you are doing raid-5 or raid-6 the performance difference is quite noticeable ( I've just recently switched my desktop from a 3ware 9650 to Areca 1220, and got a near 8% improvement in write performance, and 12% on read - raid5 5 spindles ).
So these cards are just plug n play? Just plug them in, no software or drivers required, all mirroring is managed by firmware built into the card RAID card itself?
Drivers for both 3ware and Areca are included in the CentOS-5.1 kernels.
Btw, you might want to keep an eye on some of the not-that-expensive highpoint rocketraid, hey have some fairly decent stuff coming out these days. The issues with them however, the drivers have only recently gone into the mainline upstream kernel - and their userland tools are not quite there yet. But if you need something for 2 to 5 drivers, they are an option worth considering ( they do have drivers for centos-4 and centos-5 on their website ).