[CentOS] RAID help

Thu Dec 16 09:33:41 UTC 2010
John Hodrien <J.H.Hodrien at leeds.ac.uk>

On Thu, 16 Dec 2010, Philix T A wrote:

> 1) RAID 1 is good for reading while writing is a overhead for the disk and
> may hit the performance

Write overhead is minimal, since you're just writing out the same data twice
to two equal performance drives (typically).  I'd really not worry about the
performance hit.

> 2) Dont create RAID for swap and / root partition (Not Advisable)

No, that's wrong.  Why on earth would you not want the root file system on
RAID?  And please explain the downsides of having swap on RAID1, given that
the upside should be fairly obvious.

> 3) Swap Size size should be 2X the size of the Physical memory

Historical advice.  I've got a machine with 96Gbytes of RAM, are you really
telling me I want 192Gbytes of swap?  That's just plain bad advice.

> 6) My experience had always shown if your apps had memory leak , expect
> Swapping to happen for sure,  where reboot of the apps or the system is
> needed

Then fix your memory leaks.