Comment 2 for bug 1885269

Revision history for this message
Alex Kavanagh (ajkavanagh) wrote :

Additional details from a compute unit:

on nova/compute/1 -- before stopping the unit, but after upgrading from train->ussuri on bionic. Note that the disk, console.log are owned nova.nova.

root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90-4e5e-4eb9-b29b-2befe835cbe7# ll
total 184692
drwxr-x--- 2 nova nova 4096 Jun 25 17:46 ./
drwxr-x--- 5 nova nova 4096 Jun 25 18:21 ../
-rw-r----- 1 nova nova 31316 Jun 25 17:47 console.log
-rw-r----- 1 nova nova 189136896 Jun 26 10:17 disk
-rw-r----- 1 nova nova 79 Jun 25 17:46 disk.info
root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90

After stopping the instance, the disk is now owned root.root. As there is no world-readable perm, nova now can't restart the instance.

root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90-4e5e-4eb9-b29b-2befe835cbe7# ll
total 184948
drwxr-x--- 2 nova nova 4096 Jun 25 17:46 ./
drwxr-x--- 5 nova nova 4096 Jun 25 18:21 ../
-rw-r----- 1 nova nova 31316 Jun 25 17:47 console.log
-rw-r----- 1 root root 189399040 Jun 26 10:38 disk
-rw-r----- 1 nova nova 79 Jun 25 17:46 disk.info

After fixing the permissions back to nova.nova and restarting the unit, the console.log is now owned by root, and the disk by libvert-qumu.kvm.

root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90-4e5e-4eb9-b29b-2befe835cbe7# ll
total 184924
drwxr-x--- 2 nova nova 4096 Jun 26 10:39 ./
drwxr-x--- 5 nova nova 4096 Jun 26 10:38 ../
-rw------- 1 root root 8039 Jun 26 10:39 console.log
-rw-r----- 1 libvirt-qemu kvm 189399040 Jun 26 10:39 disk
-rw-r----- 1 nova nova 79 Jun 25 17:46 disk.info

When this unit is stopped, it again goes back to root.root.

root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90-4e5e-4eb9-b29b-2befe835cbe7# ll
total 326324
drwxr-x--- 2 nova nova 4096 Jun 26 10:39 ./
drwxr-x--- 5 nova nova 4096 Jun 26 10:38 ../
-rw------- 1 root root 29040 Jun 26 10:41 console.log
-rw-r----- 1 root root 334168064 Jun 26 10:41 disk
-rw-r----- 1 nova nova 79 Jun 25 17:46 disk.info
root@juju-ed722c-mojo-17:/var/lib/nova/instances/499b7f90-4e5e-4eb9-b29b-2befe835cbe7#

The only real solution, for the moment, is to revert the permissions (as indicated in the summary) back to world readable for the disk and ../_disk/* files.