[pve-devel] [PATCH Storage] LVM Striping

[Tom Weber]

Am Mittwoch, den 26.07.2017, 20:44 +0200 schrieb Martin Lablans:
> Dear all,
> 
> this patch will change the LVM storage plugin to create striped
> rather
> than linear logical volumes, which can multiply the throughput for 
> volume groups backed by several controllers or network paths.
> 
> The number of stripes is set equal to the number of physical volumes
> in 
> the volume group (which is determined using vgs). If this number is
> 1 
> (one), linear volumes are used as before.

You're making an assumption that wouldn't hold on most of my machines
(event though they're not converted to pve yet).
- I often have SSD and HDD based physical volumes in a volume group, so
I can decide which LV I put on which PV - speed vs space
- Huge drives - esp. HDD based ones, I usually partition to get smaller
PVs (each partition a PV) for 2 reasons: 1) the PVs at the beginning of
the disk are usually faster than the ones at the end - this makes it
easier to place a LV 2) Handling of PVs (think about pvmove) is easier.

This might or might not be of interest for the regular pve user (and I
guess I'll end up hand-optimizing for my setup anyway when using pve ;)
) but I don't think automatic striping by default, just based on the
number of PVs is a good idea.

Regards,
  Tom