On Sat, 2005-05-21 at 11:22 +0200, Steven Moix - Axianet.ch wrote:
> Hello,
> In some weeks I'm going to reinstall some old RedHat9 based servers with
> Promise FastTrak TX2000 "semi-hardware" RAID1 controllers. I just tried to
> install CentOS 4.0 on a computer with a spare card and as usual both HDD
> attached to the RAID1 controller are seen separately by the installer
> because the specific driver for the TX2000 wasn't loaded. Nothing new here,
> it was always like this on every distro as far as I know.
The problem with "FRAID" (Fake/Free RAID -- even the, as you called it,
"semi-hardware" ones with DRAM) will always be that there is 3rd party
licensed code. And that code will never become GPL or even open sourced
in any way because not only does Promise (or HPT, or SilImage for that
matter) not own it, but the 3rd party that does would see their sales go
to 0 if they didn't keep it under proprietary licensure.
It's the same issue with _any_ "software-driven" hardware product. The
code is from the same 2-3 companies that the 1,000s of manufacturers
actually license from.
As you have discovered, there is the "clean-room" ataraid.c software
RAID logic and the individual hptraid.c, pdcraid,c and silraid.c FRAID
interface modules. The idea is that there is this "single" core logic
for all FRAID cards in ataraid.c, and then the independent hptraid.c,
pdcraid.c and silraid.c for each of the FRAID card vendor's products.
I'm sure it's getting dropped because it's basically impossible to keep
up with all the little changes in the interfaces or RAID logic of the
various FRAID code as well as specific FRAID card instances.
Furthermore, one change in how Windows XP handles disk geometry -- which
has been a major issue I've run into as of post-SP1, SP2 and post-SP2
hot-fixes -- when dual-booting means the interface driver could actually
destroy the fake array organization easily. The only way I see to
address this is if _everyone_ (Linux, FRAID cards, any other disk
organization/modification programs) used the LDM Disk Label (aka
"Dynamic Disk") as the "standard," which allows a lot of these details
to be stored in the disk label (exact disk geometry, journal of changes,
etc...).
Reality: FRAID is always slower than Linux LVM/MD or NT LDM. Other
than boot-time Int13h services, it offers nothing.
--
Bryan J. Smith b.j.smith@xxxxxxxx
---------------------------------------------------------------------
It is mathematically impossible for someone who makes more than you
to be anything but richer than you. Any tax rate that penalizes them
will also penalize you similarly (to those below you, and then below
them). Linear algebra, let alone differential calculus or even ele-
mentary concepts of limits, is mutually exclusive with US journalism.
So forget even attempting to explain how tax cuts work. ;->
