Default deployment does not use glance LV

[Dmitry Sutyagin]

Bug found in MOS 7.0

When Ceph is not used, Fuel allocates "image storage" space on controllers by default. However, glance configuration uses Swift as the default backend, which in turn stores it's data not in /var/lib/glance, but in /srv/node, which is essentially root partition. Therefore images are stored in root partition, while /var/lib/glance (glance LV) is not used (for storage) and just takes space.

[Alexey Stupnikov (astupnikov)]

It turns out that glance uses two kind of storages: image storage and image cache storage. Image storage is used to store objects and image chache is used as a temporary storage to cache images downloaded by users and load-balance their requests. Installed with default config, MOS uses separate partition as an image chache and uses swift as permanent image storage. IMO this information make this bug Invalid.

[Dmitry Sutyagin (dsutyagin)]

Fuel provides "Image storage" volume placement, not "image cache", AND image storage backend is not configurable, so user is misleaded and is not able to workaround via Fuel. Which makes this bug valid. Please also check for this behavior in newer versions.

[Alexey Stupnikov (astupnikov)]

Dmitry, I see your point. I thought that reported problem was about misconfigured glance, or even about a buggy MOS component. It turns out, that some fuel properties have unclear/incorrect names; it is still a bug, but it is not going to be fixed in stable branches. I will set this bug's priority to low and nominate to Newton, so developers will decide whether they should fix it or leave as is.

[Alexey Stupnikov (astupnikov)]

It turns out that we have to provide WA for bugs from support team. We have released a fix for bug #1537699 in 7.0-mu6. This fix basically allows to customize partitioning scheme on per-node basis, it may solve a problem with missing LVs. Another reported problem is incorrect LV names, the WA here is to edit nailgun fixtures for new deployments.