Re: Review of SATA RAID controllers

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Juan Carlos Castro y Castro wrote:

> Anyone has experience of any of the beasts reviewed here working
> well with Tao/RHEL? Particularly the better-recommended ones? (I'm
> willing to accept "yes, but only with Tao/RHEL 4" as an answer)
>
> http://www.tweakers.net/reviews/557


I haven't read the article yet, but I have 2 of the cards:

- Promise FastTrak S150 SX4 works with RHEL3/4, buthas no support for
any RAID level. The only RAID driver that Promise offers is for RH9
and doesn't work for RHEL3/4. The open-source driver (sata_sx4) allows
the drives to be used as individual disks, but the performance that
I've obtained is very bad (<10Mb/s) - probably the fact that data has
to be copied to the internal memory first in any direction slows down
the transfer and is not related to the driver per-se. My query to the
linux-ide list at the end of last year about progress for this driver
in terms of adding RAID support remained unanswered.

- HighPoint RocketRAID 1820A doesn't really have a "hardware RAID
engine"; if it has one it's very well hidden and it provides the same
speed as the software RAID. It's built with Marvell chip(s), but there
is so far no open-source driver for it, although Jeff Garzik (libata
author) said on the linux-ide list that a driver will be written soon.
HighPoint offers a partly open-source driver which works pretty well,
but doesn't offer any speed advantage over software RAID (md). When
using the drives as JBOD (no RAID) with md on top of them, sometimes
the driver stopped responding (and the disks were unreachable), 
although the rest of the system was fine - the only remedy is to 
reboot.

You can find some more details about SATA RAID support at:

http://www.linuxmafia.com/faq/Hardware/sata.html and
http://linux.yyz.us/sata/

-- 
Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu-PDzUyZpvkMP/PDbm/[email protected]