Re: HOWTO - Speed up IDE HD's
> fun stuff
RAID 1 is one strategy for getting 'faster' read going.
Redundant Array of Inexpensive Devices (RAID) comes in various flavors.
RAID 1 is a flavor where you take two disks of the same size and have the
computer treat them as one disk. The computer mirrors the identical data onto
both disks and can read one part of a file from one drive simultaneously as
it reads the other part of the file from the other drive. Thus reading the
whole file in half (roughly half I think) the time it would take to read the
whole file from one drive.
Of course rather than paying for two drives, you might want to just pay for
one faster drive, more RAM, or some other speed enhancer. If you already have
the drives sitting around thought, RAID 1 is something you might like.
Linux can do Software Raid. So you do not need to buy special hardware
controllers.
If you do Software Raid, to achieve the speed advantage you should put the two
disks that make up your one logical device on separate cables.
md0 stands for 'zeroeth (1st) multiple device,' a notional drive made up of
more than one real drives.
I did Software RAID 1 with two drives and SuSE 9's Installer for my desktop
box (just before converting to the Debian way :-). It was kinda tricky. I
actually bought a 2 Channel Controller PCI card so that I could have four
total (including the two on my mother board) channels and thus not have more
than one drive per cable. I have four drives you see. CD drive, back up IDE
hard drive, and two IDE drives as my RAID 1 md0.
These fancy tricks might not be worth it though if your system bus is 33MHz.
My two PIII servers have 33MHz system bus (PCI host bridge). So I don't think
it would be worth the trouble on my servers.
Someone who knows more about RAID please tell me if I am mistaken about that.
Cheers,
Roger
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