[vcenter] an empty volume with error decreases volume limits

[Ruslan Khozinov]

Description:

the creating an empty volume in cinder-vmdk az with 100GB size is failed, but volume limits was decreased on 100GB.

Steps to reproduce:

1. deploy an env with controller, compute+cinder, 2 cinder-vmdk and nova-vlanmanager.
2. shutdown one of the cinder-vmdk nodes
3. create an empty 100GB volume.
4. try to create a new volume and check volume limits

Defects:
volume limits has increased, but volume was created with error and it is not exist on vcenter datastore

fuel version: 288 (rc2)

[Ruslan Khozinov (rkhozinov)]

the same result was with an empty volume with 90GB
but empty volumes with 80 and 81 GB were create successfully

[Ruslan Khozinov (rkhozinov)]

capacity of vcenter storage is 97.07GB

[Ruslan Khozinov (rkhozinov)]

I've tried to create a vm by web vpshere client and it has limitation for a hard drive - maximum available space for vm's hard drive it's real free space of datastore about 82GB in my case.
So, could we change limitations of cinder-vmdk?

In my case the vcenter's datastore is nfs with thin-provision type for .vmdk that allows overcommit. I think it normally that we allow to create volumes with overcommitted space, but any case we should have a visible limit for maximum space of volume, that we want to create.