[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

Sat Feb 21 14:48:33 UTC 2009
Noob Centos Admin <centos.admin at gmail.com>

On Sat, Feb 21, 2009 at 6:04 PM, John R Pierce <pierce at hogranch.com> wrote:

> Kay Diederichs wrote:
> > hdparm -tT tests one type of disk access, other tools test other
> > aspects. I gave the hdparm numbers because everyone can reproduce them.
> > For RAID0 with two disks you do see - using e.g. hdparm - the doubling
> > of performance from two disks.
> > If you take the time to read (or do) RAID benchmarks you'll discover
> > that Linux software RAID1 is about as fast as a single disk (and RAID0
> > with two disks is about twice the speed). It's as simple as that.
> >
>
>
> maybe with a simple single threaded application.  if there are
> concurrent read requests pending it will dispatch them to both drives.


I'm waiting for a 10 hour backup to be completed before doing recovery on a
server (ok recovery is a nice way to put it, truth is I gave up any hope of
making the screwed LVM setup work and going to wipe/reinstall after the
backup), I'll probably be able to try some tests.

However, I don't know enough to do this properly. So some questions:

Would running two CP command to copy 2 different set of files to two
different targets suffice as a basic two thread test?

Is there a way to monitor actual disk transfers from command line without
having to do manual timing?
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