LVM *was* Re: [mythtv-users] Highest number of simultaneous streams recorded?

[Brandon Beattie]

On Fri, Oct 14, 2005 at 03:45:16PM -0500, Alex Brekken wrote:
> If one wanted redundancy only (is that RAID-0??) then I take it you would
> skip LVM entirely, correct? - IOW, are the 2 mutually exclusive or can you
> use LVM with RAID? The reason I ask is because I'm starting to put together
> some plans to build a master backend server (currently I have a
> frontend/backend combo) which will not only house myth and it's recordings,
> but also all of my music and pictures/videos of the kids. (the latter of
> which I would want the redundancy in case of a drive failure).

Raid 0 is striping for performance but no redundancy.  Any other raid
level (2,3,4,5,10) does redundancy.  LVM basically gives you virtual
partitions on top of anything that's set as an LVM partition type via
fdisk.  Some people use LVM ontop of raid.  Someone may do raid 5 for
redunancy and use LVM on top to allow them to shrink and grow virtual
partitions as they want to move space around for mount points, but still
have redunancy (Since LVM doesn't do redundancy).  The only thing like
raid LVM does is striping - but you can't resize a striped LVM partion,
so LVM striping and Raid 0 are somewhat alike.

--Brandon