[mythtv-users] CentOS vs Fedora, RAID vs LVM

Brian Wood beww at beww.org
Sat Mar 28 18:24:11 UTC 2009


On Saturday 28 March 2009 12:09:30 Ben Curtis wrote:
> Hey everyone,
>
> I have a Fedora based backend that has been running forever using a raid5
> array with LVM over top of it.  I'm going to set up a new backend to
> replace it, and have a couple of questions based on what I have read:
>
> 1) CentOS vs. Fedora
> I've used Fedora forever, however I'm tired of how often a new version
> comes out.  It's great for systems I play with, not for my main server.  Is
> CentOS supported pretty well for Myth?  I'll be running two HD5500's and a
> PVR-250 in it as a backend only.  Also, I can find a release history, but
> does it always coincide with RedHat Enterprise?  And can the RPMs from
> atrpms.net be used with it?
>
> 2) RAID vs LVM
> Do the new kernels that are shipped with Fedora and CentOS have the ability
> to use the mdadm --grow command?  If I'm just going to use one giant
> partition, is there any advantage to continuing to use LVM?  Just seems
> like one more translation that I don't need if I can grow the raid array.
> Also, what partition do you guys recommend on either?  I've used ext3
> forever, but the wiki said I may want to try something else.

LVM does not give you any performance improvement, like RAID0 does, nor does 
it provide redundancy, like RAID1 or RAID5, so it just depends on what your 
needs are. IMHO LVM just adds another layer of complexity without gainng 
much, but others will probably disagree.

Not sure if "--grow" is supported or not, I've always grown filesystems the 
old-fashioned way - back up, rebuild and restore. The drawback is you need 
the capacity to backup all your data. I use tape, but that's not too common 
these days, hard drives are cheap.

The problem with ext3 was it would block on large file deletes, but the "slow 
deletes" option pretty much fixed that. ext3 has been working for me, but you 
might want to try one of the "exotic" file systems, some are very fast at 
deleting large files, but, as I said, that's not such a problem any more. 

-- 
beww
beww at beww.org


More information about the mythtv-users mailing list