[linux-lvm] lvm mirrors

["Kevin Maguire" <k c f maguire gmail com>]

Hello

I am using LVM on SLES 10+sp2 on a test server.

$ lvs --version
  LVM version:     2.02.17 (2006-12-14)
  Library version: 1.02.13 (2006-11-28)
  Driver version:  4.7.0

I have only 2 disk devices, but noticed that newer versions of LVM
allow me to do mirroring directly in VM.  So I created a mirror via:

vgcreate vg01 /dev/sda5 /dev/sdb5
lvcreate vg01 --corelog --mirrors 1 --name XX-m \
 --size 125G

I have used /dev/md* type mirrors, built via mdadm  before.

What are the pros and cons of the 2 approaches? I have read the man
page entry for --corelog option, and appreciate the re-sync on reboot
for the mirror.

I also know that with md* type mirrors I can see current status via
/proc/mdstat, is there an equivalent for LVM mirrors? Even if I had an
extra device for logs, is there any advantage in the LVM mirroring
over the md* mirroring?

Thanks,
KM