[PLUG] Linux and >137G IDE Drives

[Fedor Pikus]

On Thu, 6 Nov 2003, Robert Kopp wrote:
> So I open the box, and out slides this controller
> card. Except for the lastest systems, they say, you
> need to use this controller because the drive is
> larger than 137G, Drivers are included for Windows, of
> course.
If your motherboard is recent enough, you don't need the new card, i
so try it first. If your motherboard IDE controller supports UDMA/100,
it'll almost certainly handle large disks, and if it supports UDMA/66
the odds are good it will too (these features are not related, they just
usually go together).

The card is most likely supported by Linux out of the box, it'll probably
be recognized by the same IDE module, if you have a recent 2.4 kernel.
I tried the cards which come with Maxtor and WD drives, they all work.

> Does Linux suffer from the same limitation? If so,
Linux supports large drives just fine. It does not even need the BIOS
support (of course it does need LBA48 from the controller, otherwise the
bus just does not have enoug bits to address the disk and it cannot be fixed
in software).

> Oh, yes. If it doesn't seem suitable for installation
> inside the computer, could it be used in a FireWire
> enclosure without the controller?
It should work fine inside, I have a 250G disk in my PC and a 160G one,
no problem. But if you want to go external, you can get an enclosure
which converts IDE to USB2 or Firewire. They are about $60 at Fry's or you can
get them from the net for half of that (newegg sells USB enclosure for
$30 now). You need to make sure they have large disk support, most new ones
do but if you buy from ebay you should ask.
Now we get to really interesting stuff, whether that will work with your
Linux box.
I obviously haven't tried ALL distributions, but I know that stock Linux
kernel has a problem with USB-2 and if you try to copy several GB of data
onto external USB2 disk it'll lock up. RedHat patched their kernels, since at
least 2.4.18 they work just fine, I often write out over 150GB of stuff on
USB disk in one command.
I don't have a firewire disk, I do use Firewire-to-SCSI module (sbp2), and
it works for stuff like scanners, I just don't know how stable it is for
large disk (on the other hand, my scanner can send several GB of data when
it scans a roll of film, and I never had problems with it).
-- 
                                  Fedor G. Pikus
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