disks configuration spontaneous changed to the default

[Ilya Kharin]

I have some strange issue with Fuel. The env consists of one controller node and two nodes with "compute" and "cinder" roles, the compute nodes also have a special configuration of disks. After some time of the operation of this environment I noticed that the configuration of disks was spontaneously changed for compute nodes to the default. However fortunately the changes was not deployed.

Fuel version: http://paste.openstack.org/show/4jwumNPKrtwOwO0yqYvT/

[Roman Prykhodchenko (romcheg)]

Could you please attach a diagnostic snapshot?

[Oleg S. Gelbukh (gelbuhos)]

We've noticed that this situation occurs after we create a Cinder volume (LVM backed) in OpenStack. Nailgun agent detects that LVM volume as new device, and seems to rescan and rebuild disks configuration for the node. This rebuild overrides existing configuration.

See disks configurtion in Nailgun DB after the rebuild in attachment.

[Ilya Kharin (akscram)]

The size of the diagnostic snapshot is approximately 2.5GB I'm soon going to attach some extracts from it.

The problem had occurred after the master was upgraded from 5.1 to 5.1.1 (nightly build - you can look on the exact version that was posted on the paste earlier). The upgrade was made because of the fix of the *oslo.messaging* library in 5.1.1. After the upgrade the configuration of disks on the nodes with the "cinder" role began to change. Volumes (iSCSI disks) on the nodes began to appear as a disks in attributes of disks. I've attached the sample of the attributes configuration.

[Roman Prykhodchenko (romcheg)]

@Ilya: You can re-pack the snapshot to LZMA, that should significantly shrink its size.

[Oleg S. Gelbukh (gelbuhos)]

Please, be informed that odd disk configuration caused not by creation of Cinder volume, but by attachment of such volume. Resulting device lands in /dev/disk/by-path and Nailgun agent discovers it as a new sdX device.

[Irina Povolotskaya (ipovolotskaya)]

Added to 6.0 RN within https://review.openstack.org/#/c/133014/