openstack
/
fuel-upgrade
Code Issues Proposed changes

Make sure fuel_agent builds IBP images in a proper directory 

Use /var/lib/fuel/ibp as the image build directory. This directory
will be backed by a volume in the mcollective container which reduces
IO overhead and makes image build time reasonable.

fuel_agent (which builds Ubuntu images) runs in the mcollective
container. 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)

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

Note: this patch can be merged before the ones which actually make
/var/lib/fuel/ibp a host volume (obviously there won't be any
performance gain until fuel-library/fuel-main bits get merged).

Merge-After: https://review.openstack.org/201947
Related-Bug: #1457643
Change-Id: Ic4d258523aa13b3879a730edb2d910522ec24c93
This commit is contained in:
Alexei Sheplyakov 2015-07-03 11:08:42 +03:00
parent d1d8f61f24
commit 8712ac1fdf
1 changed files with 5 additions and 0 deletions
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5
fuel_upgrade/config.py
View File

@ -334,6 +334,10 @@ def config(update_path, admin_password):
('/var/lib/fuel/keys', {'bind': '/var/lib/fuel/keys',
'ro': False})],
'volume_fuel_ibp': [
('/var/lib/fuel/ibp', {'bind': '/var/lib/fuel/ipb',
'ro': False})],
'volume_postgres_data': [
('{0}/postgres'.format(container_data_path), {
'bind': '/var/lib/pgsql',
@ -429,6 +433,7 @@ def config(update_path, admin_password):
'volume_ssh_keys',
'volume_dump',
'volume_fuel_configs',
'volume_fuel_ibp',
'volume_keys']},
{'id': 'rsync',