Cached images duplicated per host

[Kendrick Luong]

Cinder cache using NFS backend creates duplicate cached images per host.

Currently if you bring up an instance with image A on host A, first launch will cause it to download from glance and cache. On subsequent builds if instance is allocated to host A then it will refer to cache.

If a subsequent build get allocated to host B, then the image is downloaded again from glance and cached. In the tenant project for the cinder cache you can see a duplicate volume image name, admin volume list the 2 images against host A and B

[Sofia Enriquez (lsofia-enriquez)]

Hi Kendrick Luong, hope this message finds you well.
- what version of openstack are you using?
- Do you mind sharing the steps to reproduce this bug?
Thanks,
Cheers

[Kendrick Luong (kendrickluong1234)]

We are running openstack zed

Our environment has 4 hosts running with a common NFS share for cinder
1. Upload image
2. Launch 1 x instance of image
3. Check cinder-cache project for cached image volume
4. Launch 4 x instance of image, look at host distribution
5. Check cinder-cache project, duplicate image volume created for new host image volume is started on
6. Check admin volumes page, multiple image caches for each host