diff options
| author | Jenkins <jenkins@review.openstack.org> | 2012-09-06 19:40:41 +0000 |
|---|---|---|
| committer | Gerrit Code Review <review@openstack.org> | 2012-09-06 19:40:41 +0000 |
| commit | c29f6d27a8de2e475b06ba3123f65b658eff72e5 (patch) | |
| tree | 223a17a18973c4006348335d7c870f866ce0c460 | |
| parent | f14bf21152fb996897acf5e46a5dbdff832318c2 (diff) | |
| parent | 64f1916d5871344bdd5177993bca709950e0b819 (diff) | |
| download | nova-c29f6d27a8de2e475b06ba3123f65b658eff72e5.tar.gz nova-c29f6d27a8de2e475b06ba3123f65b658eff72e5.tar.xz nova-c29f6d27a8de2e475b06ba3123f65b658eff72e5.zip | |
Merge "avoid the buffer cache when copying volumes"
| -rw-r--r-- | nova/volume/driver.py | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/nova/volume/driver.py b/nova/volume/driver.py index dee0df953..d03ad7cdc 100644 --- a/nova/volume/driver.py +++ b/nova/volume/driver.py @@ -112,9 +112,20 @@ class VolumeDriver(object): volume_name, FLAGS.volume_group, run_as_root=True) def _copy_volume(self, srcstr, deststr, size_in_g): + # Use O_DIRECT to avoid thrashing the system buffer cache + direct_flags = ('iflag=direct', 'oflag=direct') + + # Check whether O_DIRECT is supported + try: + self._execute('dd', 'count=0', 'if=%s' % srcstr, 'of=%s' % deststr, + *direct_flags, run_as_root=True) + except exception.ProcessExecutionError: + direct_flags = () + + # Perform the copy self._execute('dd', 'if=%s' % srcstr, 'of=%s' % deststr, 'count=%d' % (size_in_g * 1024), 'bs=1M', - run_as_root=True) + *direct_flags, run_as_root=True) def _volume_not_present(self, volume_name): path_name = '%s/%s' % (FLAGS.volume_group, volume_name) |