[linux-lvm] Whats wrong with this picture?

[Andreas Dilger]

On Jan 22, 2002  00:45 +0000, James Hawtin wrote:
> --- Physical volume ---
> PV Name               /dev/ide/host2/bus1/target0/lun0/part4
> VG Name               sunset_vg
> PV Size               11.24 GB / NOT usable 51.50 MB [LVM: 125.00 KB]
> PV#                   2
> PV Status             available
> Allocatable           yes (but full)
> Cur LV                4
> PE Size (KByte)       32768
> Total PE              358
> Free PE               0
> Allocated PE          358
> PV UUID               0jqg8y-LkA2-vZ1w-jHpv-cSY6-t7sh-BcmDS6
> 
> My PE size 32M yet my unusable space is > 32M 
> 
> I tested this with different PE sizes and found that the unusable space
> reported is aways in the range >= 1PE and < 2PE
> 
> I would have expected it in the range >=0PE and <1PE
> 
> Why is this not so?

Because the Sistina folks changed it in a recent tools release to have
a _full_ empty PE available for future expansion.  IMHO that is a bit
of a waste, especially if you have large PEs.  I would much rather that
it reserve some minimum amount of free space (e.g. 4MB or whatever) and
then it doesn't need to waste so much.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/