<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'Sans Serif'; font-size:10pt; font-weight:400; font-style:normal;">On Sunday 21 June 2009 14:26:27 David Zanetti wrote:<br>
> On Thu, 2009-06-18 at 12:57 +1200, James Booth wrote:<br>
> > Thanks Steve. RAID1 with LVM will give me what I need, I was just<br>
> > hoping for RAID 1+0 so I could also get the performance gain, which<br>
> > may be handy if I end up with three frontends all watching and<br>
> > recording HD at the same time.<br>
><br>
> For read streams, software RAID-1 will scatter the workload over both<br>
> disks. So if you have a few front-ends reading, it won't actually be<br>
> single-disk performance.<br>
><br>
> Write in *all* RAID modes has a penalty, it's a fair bit lighter in 1<br>
> than 5 purely because 1 involves writing to less disks to update a<br>
> block.<br>
><br>
> My preferred approach is RAID-1 pairs with LVM spanning the whole set.<br>
> This gives me good reliability without too much loss in performance, and<br>
> an easy migration path to more storage, thanks to various uses of<br>
> degraded array modes.<br>
><br>
> RAID-5 only makes sense if you are seriously strapped for cash or<br>
> physical space to put disks. Otherwise, the write performance is slower,<br>
> the failure cases are a bit more hairy, and expansion is even hairier.<br>
><br>
> Go with simple disk systems, people! I've lost enough over the years to<br>
> pushing my luck, and you really want simple arrangements.<br>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><br></p>Yep, that's just what I've gone for. Splashed for an extra HDD and now have 2 x RAID-1 with LVM spanning them (non-striped, to make future expansion easier). Have gone with XFS, and everything seems good.</p></body></html>