[CentOS] Freeing pv space for snapshots

Thu Jan 4 19:58:30 UTC 2007
Kevan Benson <kbenson at a-1networks.com>

On Thursday 04 January 2007 11:43, Paul wrote:
> After upgrading my HD, I am now wishing I left some space for doing
> snapshots.  Is there a way to free up some space so I can get some free
> PE?
>
> Right now I have this:
> # vgdisplay
>   --- Volume group ---
>   VG Name               VolGroup00
>   System ID
>   Format                lvm2
>   Metadata Areas        1
>   Metadata Sequence No  7
>   VG Access             read/write
>   VG Status             resizable
>   MAX LV                0
>   Cur LV                2
>   Open LV               2
>   Max PV                0
>   Cur PV                1
>   Act PV                1
>   VG Size               38.22 GB
>   PE Size               32.00 MB
>   Total PE              1223
>   Alloc PE / Size       1223 / 38.22 GB
>   Free  PE / Size       0 / 0
>   VG UUID               0mB18U-4VRo-1GMC-oKdf-ZndA-slFy-eOQtYD
>
> So, it won't let me do this:
> # lvcreate -L1G -s -n fullbakup /dev/VolGroup00/LogVol00
>   Insufficient free extents (0) in volume group VolGroup00: 32 required
>
> Ext2online will not reduce size, so the man page says and I also tried it
> for the fun of it.
>
> lvresize won't work either.

ext2resize is what you are looking for, but it requires the mount to be 
offline.

In your case, you want to ext2resize the ext2/3 partition to reduce it's usage 
of the LV, then use lvresize to reduce the LV appropriately.  That should 
leave you the room in the Volume Group to create snapshop LVs.

-- 
- Kevan Benson
- A-1 Networks