[linux-lvm] Time needed for take a snapshot

[Zdenek Kabelac]

Dne 19. 01. 20 v 13:59 Gionatan Danti napsal(a):
> Hi list,
> just for confirmation: is the time needed to take a snapshot constant, or does 
> it depend on how many chunks are mapped in/by the specific thin pool and 
> volume? In other workds, is snapshot create time O(1) or O(n)?

Hi

Depends on what you are asking -  in lvm2 - unfortunately some parts of the 
code are sometimes even O(n^2) - so the more LVs are in VG - the 'heavier' the 
operation gets.

So having  thousands of LVs in a single VG will become probably your bottleneck.

The bTree mapping in kernel will probably be less problematic here.

Regards

Zdenek