[linux-lvm] -l 100%FREE doesn't work with RAID1

[Alasdair G Kergon]

On Wed, Jan 20, 2016 at 12:19:13PM +0000, Bryan Larsen wrote:
> I'm setting up some provisioning scripts, so I don't know the actual sizes
> of the hard drives
> $ sudo lvcreate --type raid1 -m 1 -l 100%FREE -n backups hdd_vg
>   Insufficient free space: 781320 extents needed, but only 390658 available
> $ sudo lvcreate --type raid1 -m 1 -l 50%FREE -n backups hdd_vg
>   Insufficient free space: 390662 extents needed, but only 390658 available

Works for me here.

Perhaps you're using an old version?
When run with -vvvv, the key line for me is this one
metadata/lv_manip.c:3036   Found fewer allocatable extents for logical volume lvol1 than requested: using 48 extents (reduced by 142).
 
Alasdair