Re: Can linux support hotswap ?

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• In reply to: Darick: "Can linux support hotswap ?"
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Date: Sat, 5 Jun 2004 19:29:49 +0200

Hi Darick,

i think you mixed something up ..

If you want to increase your data's integrity against harddisk failures,
you need to set up a "raid array". For common integrity use, you should take
RAID-1 (mirror) or RAID-5 (spread parity)
Please refere to a complete Documentation, if you need more detail on that..

Linux (e.g. Red Hat v9.0) supports a Software-Emulation of RAID-Technology..
..afaik, it does by offering kernelspace driver to define an disc array and
let them (/dev/md*)
behave like a regular disc .. so you can e.g. create partitions and format
the
whole array as doing it for example with /dev/hda

Exchanging a Disc while your Linux Box is running should not be a problem
for your Linux
(at least for Software-side) .. as far as you 're not running your System on
this disc array *g*:
Unmounting and unloading the controller driver before taking the disc out of
your system should work..
but I'm confident that your Hardware e.g. your disc controller WILL NOT like
it.

If your System really needs to be kept up despite an harddisc failure, I'd
advise you to
take an Disc Controller that already supports RAID (take care of
"hotswap/hotspare"
capability). A good choice are 3ware raid-controller .. they all provide
good-working
and feature-filled Linux Software..

This time, your HW-Controller does the "disc array -> disc" emulation.. So
for your Linux,
the array seems to be a regular harddisc.. using the provided Linux-Software
you can control
your HW Raid-Controller's Emulation.

Now your Controller is made to take a disc off while running your system, so
it could manage it
silencely: After having your corrupt disc exchanged your controller will
initialize the new disc - e.g.
if you're using mirror (RAID-1), it will copy existing data to the new disc
automaticly..

Hope, i' could fill your question ..
Regards

Fatih Gey

P.S.: http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html gives you a good
overview about
RAID

"Darick" <darick_ang@yahoo.com.sg> schrieb im Newsbeitrag
news:72gqb0t7cc487rnmhd5rco83ra3u3i6psj@4ax.com...
> first, i like to know, can linux support hotswap ? i using RH9, may i
> know how to configure ?
>
> second, i like to know how hotswap mirroring the data ? i hope is not
> on file basis

• Previous message: Michael Heiming: "Re: Problems with FLOCK (file lock)"
• In reply to: Darick: "Can linux support hotswap ?"
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