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

[David Brodbeck]

Brian Wood wrote:
> 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.

It's useful in a couple of specific situations, neither of which applies 
very often to Myth:

- You have multiple partitions on the device and you might need to 
reallocate space between them.  This is much easier with LVM than 
without it.

- If you think you might want to add a second array, and want one 
contiguous storage space.  You can grow your LVM volumes onto the second 
array seamlessly.  There's very little reason to do this with MythTV, 
though, now that Storage Groups exist.

Generally I agree with you, though.  The mdadm+LVM+fs stack is complex 
and sometimes problematic.  I think it was more common in the past 
partly because it didn't used to be possible to partition an mdadm array.