[Lustre-discuss] software raid

[Temple Jason]

I believe that software raid has a historical bias.  I use software raid exclusively for my lustre installations here, and have never seen any problem with it.  The argument used to be that having dedicated hardware running your raids removed any overhead from the OS having to control them, and that raid in general took too much cpu and memory, but the md stack has been drastically improved since those times (over a decade), and now I see very little evidence of this being a problem.

My argument against hardware raid is that if you lose a controller, you lose the raid completely.

Just my 2cents.

Jason

-----Original Message-----
From: lustre-discuss-bounces at lists.lustre.org [mailto:lustre-discuss-bounces at lists.lustre.org] On Behalf Of Brian O'Connor
Sent: giovedì, 24. marzo 2011 03:55
To: lustre-discuss at lists.lustre.org
Subject: [Lustre-discuss] software raid


This has probably been asked and answered.

Is software raid(md) still considered bad practice?

I would like to use ssd drives for an mdt, but using fast ssd drives
behind a raid controller seems to defeat the purpose.

There was some thought that the decision not to support
software raid was mostly about Sun/Oracle trying to sell hardware
raid.

thoughts?

-- 
Brian O'Connor
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