On Tue, Jun 12, 2012 at 8:20 AM, Pádraig Brady <p...@draigbrady.com> wrote: > On 06/12/2012 04:07 PM, Fredric Morenius wrote: >> From: Scott Moser [mailto:ssmos...@gmail.com] On Behalf Of Scott Moser >> Sent: den 11 juni 2012 23:16 >> >>> ...Without digging around on older versions of OS's and their included >>> kernel/udev/kpartx.... i'd have to say that from your message above, and my >>> testing that running 'kpartx' is no longer necessary. That can reasonably >>> be expected to be created by >the kernel or some other plumbing bits >>> automatically... >> >> I just now tested to remove the kpartx invocation from >> /nova/virt/disk/mount.py, like this: >> >> diff --git a/nova/virt/disk/mount.py b/nova/virt/disk/mount.py >> index 11959b2..4d9527b 100644 >> --- a/nova/virt/disk/mount.py >> +++ b/nova/virt/disk/mount.py >> @@ -61,25 +61,9 @@ class Mount(object): >> if self.partition == -1: >> self.error = _('partition search unsupported with %s') % >> self.mode >> elif self.partition: >> - map_path = '/dev/mapper/%sp%s' % (os.path.basename(self.device), >> - self.partition) >> - assert(not os.path.exists(map_path)) >> - >> - # Note kpartx can output warnings to stderr and succeed >> - # Also it can output failures to stderr and "succeed" >> - # So we just go on the existence of the mapped device >> - _out, err = utils.trycmd('kpartx', '-a', self.device, >> - run_as_root=True, >> discard_warnings=True) >> - >> - # Note kpartx does nothing when presented with a raw image, >> - # so given we only use it when we expect a partitioned image, >> fail >> - if not os.path.exists(map_path): >> - if not err: >> - err = _('partition %s not found') % self.partition >> - self.error = _('Failed to map partitions: %s') % err >> - else: >> - self.mapped_device = map_path >> - self.mapped = True >> + #qemu-nbd already has mapped the partition for mounting >> + self.mapped_device = '%sp%s' % (self.device, self.partition) >> + self.mapped = True > > Looks good. That should also support raw through the /dev/loop%s devices. > > It might be safer to fallback to kpartx if not exists ... > '%sp%s' % (self.device, self.partition) > That would support kernels before 3.2 > I'd also add a comment in the code, that nbd must be mounted with param > max_part=16 or whatever.
Might be totally unrelated to the above issues but I figured I'd throw it out there. I was messing with file injection today and was getting odd errors. Some were due to hitting errors on a previous boot and partitions not getting cleaned up (e.g. kpartx -d never ran and the /dev/mapper/nbd* entries were still there, or qemu-nbd was still running). Some of those were likely a result of my own circumstances. More interesting though, and what might be of use to other people, the "kpartx -a" calls get run and then the code in nova/virt/disk/mount.py immediately checks for whether or not the newly created /dev/mapper/nbdXXpX partitions exist. They'd actually get created but the os.exists call would fail. Apparently the os.exists call was getting run too soon. I added a time.sleep() after both the 'kpartx -a' and 'kpartx -d' calls, to give things time to catch up before the os.exists calls and things worked much better. _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
