I'm a DBA familiar with lvm snapshotting for database backups and have now been tasked with rectifying a "siloed" lvm setup. Essentially, I now have a standalone bare metal box that is running 3 mysql instances across 3 ports. The unfortunate thing is that it seems like each of the 3 disks has been mapped to one of 3 volume groups, which has then been turned into 3 different logical volumes. This kind of avoids the abstraction layer that lvm provides entirely.
Aside from that...
I'm essentially trying to find out just how much space I have left on the system. df -h shows just about a free terabyte, however, pvscan shows that there is only about 100GB free (total) on the physical volumes.
My questions are: Does pvscan trump df -h in reporting actual amount of space left in my lvm setup? Is it possible for someone else to have set up logical volumes (using the -L switch) to present to the OS a much larger amount of space than what it has in its underlying phycal volumes?
Thanks guys! I know this setup might sound wierd but any insight is greatly appreciated! Ask me a mysql question and I'll be happy to assist where I can.
Thanks again!
uname -a
Linux wrhs01 3.2.0-0.bpo.4-amd64 #1 SMP Debian 3.2.41-2~bpo60+1 x86_64 GNU/Linux
