[mythtv-users] Re:Question on software RAID

[Peter Loron]

Martin Smith wrote:

> Dave Zanetti Wrote:
> 
> 
>>On Mon, 26 Jan 2004, Peter Loron wrote:
>>
>>
>>>Once I construct a software RAID-5 under Linux, is it possible to later
>>>expand the array with more disks without erasing the contents? I'm
>>>trying to plan for my Myth box...
>>
>>Nope.
> 
> 
> There's a utility called raidreconf that can allgedly do this. Whether you'd
> risk using it is another question and I haven't tried it myself:
> 
> http://unthought.net/raidreconf/
> 
> 
>>But, you could use a LVM on top of the RAID-5 set, and when you want more
>>disk added, create another RAID-5 set and add it to the LVM.
> 
> 
> True, but this requires another 3 disks of course.
> 
> Personally I'd recommend using LVM regardless of the underlying disk
> arrangement. It's just so much more flexible.
> 
> Martin

Ok, so sounds like build the array, then LVM on top of that. What is the 
performance penalty for that extra layer? Once I need to expand later, I 
  can just add another RAID5 array into the LVM "disk"...does the LVM 
overhead go up significantly as you add more volumes to it?

The backend I'll be using is a 1.6Ghz AthlonXP, 512MB ram so I don't 
expect it to be too much of an issue.

Thanks!

-Pete