Comment 3 for bug 1387087

As far as I can see from live monitoring with atop,
LVM | image-glance | busy 94% | read 0 | write 242 | KiB/r 0 | | KiB/w 3 | MBr/s 0.00 | MBw/s 0.38 | avq 1.01 | avio 7.59 ms |
DSK | sdb | busy 94% | read 0 | write 345 | KiB/r 0 | | KiB/w 2 | MBr/s 0.00 | MBw/s 0.38 | avq 1.01 | avio 5.32 ms |

There is no read/write load rate at all but sdb and image-glance LVM are *extremely* busy...
According to atop man "Disk: A busy percentage of 70% or higher is considered ‘critical’."