Description of problem:
lvcreate (8) create mirror set of an lvol with -m1 option.
In order to create mirror succesfully, we need to populate
3 PVs within its VG. Following requirement is only written
"Example" section of the lvcreate man page.
> This operation would require 3 devices - two for the
> mirror devices and one for the disk log.
This requirement should be noted in -m section of the
lvcreate's online man page, as well.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. man lvcreate
In version 2.02.28 is in added to lvcreate man page this formulation to the -m option description:
The optional argument --mirrorlog specifies the type of log to be used. The default is disk, which is persistent and requires a small amount of storage space, usually on a separate device from the data being mirrored. Using core means the mirror is regenerated by copying the data from the first device again each time the device is activated, for example, after every reboot.
RHEL 5.2 include lvm2 2.02.32, so it should be fixed already.