SATA software RAID-inkernel vs hardware

[Miroslav Lachman]

Marcin Jessa wrote:
> Hi guys.
> 
> I need to set up a server with two RAID1 SATA drives to do mirroring.
> I was wondering if there was any point in using software RAID
> controllers like FastTrak S150 TX4.
> I've found some info avaliable for Linux and people say kernel raid is
> as good as any BIOS raid. Would that be true for FreeBSD as well?
> Also using a PCI card for the disc drives in place of the built in SATA
> interface may degrade performance, since the built in SATA is probably
> on a different PCI bus to plug in cards. 

AFAIK built-in RAIDs on cheap mainboard are on the same bus, as plug in
PCI cards sharing same IRQ. Some manufacturers are explaining this in
manuals.
Few months ago I was testing built-in SATA RAID on older ASUS board
(with Silicon Image onboard SATA RAID). BIOS RAID was unstable and I was
not able to found why. Then I setup gmirror which was OK.
But all was just home testing, never used in production.

> So what would you guys suggest? Keep the card or go for inkernel
> implementation?
> 
> Marcin. 

So my suggest is real HW RAID card (if you have money), or gmirror, but
not onboard "pseudo raids".

Miroslav Lachman