Re: Cheapest "software" RAID card
Andy Smith wrote:
>On Mon, Oct 24, 2005 at 04:46:21PM +0800, Jason Lim wrote:
>>I have been investigating cheap "software" or "host-based" RAID cards.
>>They tend to be magnitudes cheaper than real hardware RAID cards like
>>3ware/AMCC. But for some purposes, you don't care about the CPU overhead,
>>but do want something hardware (not md software raid) especially when your
>>on-board controller is crap.
>Why do you want to use the "fake hardware RAID" of these cheap
>controllers? They are outperformed by Linux md and Linux md has the
>advantage that it is portable and open source.
>Silicon Image, Rocketraid, Promise, these all perform well, but I
>would never ever use their "fake RAID".
>>Could anyone tell me which cheap "software" RAID card works best right
>>now, in that I can put in a Debian install disk and the stock kernel
>>detects the RAID card and the array on it (more or less like you would
>>with a 3ware or other cards, but without the better performance)?
>I've had no issue using Sarge's Debian Installer to install to
>Silicon Image SATA controllers.
Mu understanding is that NONE of these cards are supported because the
people writing the linux drivers for them (at least the ones included in
the kernel) are not the people making the hardware, they are linux
developers/users and they know that there is no point re-inventing the
wheel when linux already has md which would outperform a new
implementation of RAID as mentioned above. Also I doubt Linus would
allow the bloat of another RAID implementation in the kernel, let alone
several (one for each different card).
What would be interesting is if the drivers for these cards could be
modified to hook the md subsystem in linux and transparently create the
array automatically, but thats not what currently happens.