e1c00fb8d8
Makes IBP images build time reasonable, especially if the master
node runs in a VM.
fuel_agent (which builds Ubuntu images) runs in the mcollective
container. In general OS setup generates quite a lot of IO.
fuel_agent builds the OS image in a loopback filesystem, which
results in an extra overhead. A container filesystem is backed
by dm-snapshot which is known to have a poor write performance,
especially for large files (like OS images). By default docker
storage is a loopback file residing in /var/lib/docker. Thus
the data written to the OS image being built goes through a number
of layers:
ext4 -> loop -> dm-snapshot (/var/lib/docker-> loop ->
-> ext4 (/var/lib/docker) -> dm-linear (os-varlibdocker) ->
-> hard drive
If the master node runs on a VM rather than a physcial hardware
the above chain gets even more complicated:
ext4 -> loop -> dm-snapshot (/var/lib/docker-> loop ->
-> ext4 (/var/lib/docker) -> dm-linear (os-varlibdocker) ->
-> virtual hard drive (qemu) -> qcow2 -> ext4 (host)
The write performance of such a setup is awful, as a result making
the basic Ubuntu installation takes more than 15 minutes.
Using the volume makes it possible to eliminate the extra layers,
so the written data goes through
ext4 -> loop -> ext4 -> dm-linear (os-var) -> hard drive
Related-Bug: #1457643
Change-Id: Id50bbea95aced153aedf831deea15025bd69c406
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| .. | ||
| dockerctl | ||
| dockerctl_config | ||
| dockerctl-alias.sh | ||
| functions.sh | ||
| get_service_credentials.py | ||