[CentOS] ZFS @ centOS

Tue Apr 5 19:29:30 UTC 2011
Chuck Munro <chuckm at seafoam.net>

On 04/05/2011 09:00 AM, rainer at ultra-secure.de wrote:
> That is really a no-brainer.
> In the time it takes to re-build such a "RAID", another disk might just
> fail and the "R in "RAID" goes down the toilet. Your 19-disk RAID5 just
> got turned into 25kg of scrap-metal.
> As for ZFS - we're using it with FreeBSD with mixed results.
> The truth is, you've got to follow the development very closely and work
> with the developers (via mailinglists), potentially testing
> patches/backports from current - or tracking current from the start.
> It works much better with Solaris.
> Frankly, I don't know why people want to do this ZFS on Linux thing.
> It works perfectly well with Solaris, which runs most stuff that runs on
> Linux just as well.
> I wouldn't try to run Linux-binaries on Solaris with lxrun, either.

During my current work building a RAID-6 VM Host system (currently 
testing with SL-6 but later CentOS-6) I had a question rolling around in 
the back of my mind whether or not I should consider building the Host 
with OpenSolaris (or the OpenIndiana fork) and ZFS RAID-Z2, which I had 
heard performs somewhat better on Solaris.  I'd then run CentOS Guest OS 
instances with VirtualBox.

But ...
I've been reading about some of the issues with ZFS performance and have 
discovered that it needs a *lot* of RAM to support decent caching ... 
the recommendation is for a GByte of RAM per TByte of storage just for 
the metadata, which can add up.  Maybe cache memory starvation is one 
reason why so many disappointing test results are showing up.