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Re: [Xen-users] RAID-1 strategy for a Xen/CentOS server?

To: "Tom Brown" <xensource.com@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] RAID-1 strategy for a Xen/CentOS server?
From: "Bob Tomkins" <bob.r350@xxxxxxxxx>
Date: Fri, 7 Dec 2007 13:26:13 -0800
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??? By definition, "failover" requires redundant hardware,

Yes.  And I since I'm considering RAID1, I have 2, redundant hardDrives on this box.

Maximizing failover to the extent possible on this box addresses *DISK* failover, and nothing more.

you meant by hardware vs software RAID...

Here, simply the differences -- in application & utility -- between the SATA RAID-1 provided  "on the motherboard" (hardware), versus the options of Software RAID Mirroring ( e.g., http://aplawrence.com/Linux/softmirror.html, FreeBSD's Vimum/GEOM, etc etc)
it is basically irrelevent

LOL.  Clearly you've not been a contributor to some of the fanatical this-or-that-filesystem arguments I've stumbeld across.

but ext3 should be fine.

It sounds like there's no specific requirement.  Hence, agreed.
I can't really imagine a scenario where the more
esoteric filesystems would be needed... but I'm no expert, and when you
get into journalling filesystems (in the domUs) there are some complex
interactions ( e.g. preserving the order of writes, which is one reason why
using real block devices instead of files may be better).

(Then again, using disk files for filesystem images probably conflicts
with maximizing failover capabilities... this may depend on how many domUs
you have, and whether you need/want to be able to fail them over

I'm at a point where I need to (re)read what I've found and consider well your comments/question.  That's what weekends are good for!


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