Hi, folks. I'm looking at taking a software repository of some 200 Gigabytes
that lives on a Terabyte RAID array and creating LVM snapshots in order to
be able to backup the snapshot, not the active file system, and avoid some
of the "files changing while doing backup" problems I'm having with the
Amanda setup. But I have some related questions.

1: How long does the snapshot process take, typically? Since I'll need to
freeze the main filesystem to get a good snapshot, I don't want to freeze it
for too long, or the people who need the data will get upset.

2: Which kernel should I be using? I'm seeing various notes about
file-system locking features that may or may not be supported in specific OS
releases: I'm comfortable with RedHat and its variants, so I'd be
comfortable using Centos 4 or Fedora Core 2 or better, but will I need to
rebuild my kernel with added options and prevent auto-updates of my kernels
to avoid losing important locking features?

3: What filesystem best supports this? I see notes about people using ext3
and JFS for this stunt, but am not sure what is best for this application.
Good performance under heavy I/O is critical for what I'm doing.