[clug] a few LVM questions

[Andrew]

Hi All,

I'm running a few virtual machines on a LVM volume (and I have some 
space on the base partition for snapshots).

I have been allocating 3GB  for a snapshot (and then rsync the vm's to 
another server).  I was wondering if there is any way to work out how 
much of this space is actually being used? (I googled and found a few 
other people with the same question.... but frustratingly all the howtos 
I found didn't answer this question) Likewise I am curious to know what 
happens if it fills up (what errors should I check for, and where)?

I also noticed that when I create the snapshot it blocks all writing for 
the virtual machines when the snapshot is being created (which does 
create some problems from time to time), googling around said that this 
wasn't a problem in earlier kernels, but some other users have noticed 
this as well.   Anyhow, was wondering if anyone else had experienced this?


Other info:  Running Debian Lenny (64 bit, 2.6.30 kernel) + 4 x 15,000 
146GB SAS Drives in RAID 5.


Cheers,
Andrew