Tim Small <tim@...> wrote:
>On 13/10/10 08:00, fortaisur wrote:
>> I noticed a problem I didn't notice before: running smartd seems
>> to take an Intel SSD out of DMA mode. Here is a demonstration of
>That's arguably a Linux bug, I'd say. Can you use an libata driver
>instead, e.g. force the use of the libata PIIX driver, instead of the
>old-IDE piix driver, or put the controller into AHCI mode, or use an
>sil3132 PCIe card or similar? Note that the libata drivers use the
>/dev/sd? namespace, so you'll need to make sure you don't have /dev/hda
>hard-coded if you use this.
>On the plus side, if you use AHCI, or the Sil card then you'll get NCQ
>(which you won't with PIIX), and thus better performance (hdparm -t just
>gave 250M per second on a similar Intel 80G SSD using ahci on this
Thanks for the response.
It's a VIA M800 Mini-ITX unit, it has a single PCI slot but there
isn't much room so I doubt I could use a card.
I don't know how to try different drivers.
Wikipedia says that AHCI is supported in kernel 2.6.19, the
current RHEL5/CentOS is 2.6.18-194.17.1 so maybe I can't try
that; don't even know if the PC supports it.
I poked around in the AwardBIOS, I see nothing to tell it use
AHCI or an alternate SATA non-emulation mode or anything like
In a web search I found mention to try "hda=noprobe hda=none" but
that failed early in booting, it can't find various /dev items,
goes into kernel panic, so won't work on this existing built