[linux-lvm] what use is virtualsize -- or how is it to be used?
Linda A. Walsh
lvm at tlinx.org
Fri Jul 8 05:22:54 UTC 2011
I just saw it in the man page, and first thing I tried was creating a
by just giving a --virtualsize, arg -- thinking it would 'auto-extend
it' as needed.
Next was looking on the net and seeing an example that gave it some
small size (-L 1G),
with a virtual size of 2G. So what is that supposed to do?
I just now thought to copy a bunch of files ( that differed from
yesterday to today) to a tmp
partition) but had it fail miserably when it REALLY failed upon reaching
limit -- not the virtual limit!)....
I was trying to use rsync to copy from a snap from yesturday of /home
that was mounted on
/ohome to 'home.diff' (the partition that I used 'virtual size' with,
... I gave it a real
size of 1G, and a virtual size of 1T.
Using rsync, I had --compare-dest=/ohome (where I mount yesturday's
snap) and copied
from /home to /home.diff (the virtual partition).... Well the diffs
were > 1G, so had
hoped /home.diff would expand to it's virtual size... Anyway, got I/O
errors, after I
ran out of space. Ok, so *that*'s not what virtual size is for...either!
Anyway, I unmounted the now 'corrupt' /home.diff, and tried to remove it...
Got all sorts of i/o errors using lvremove Home.diff. (-f didn't work
Got it to remove with lvremove -f /dev/PV/Home.diff
That gave I/O errors too, but successfully completed...
So what's virtual size good for, anyway?
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