yahoo-eng-team team mailing list archive

[Sean Dague <sean@xxxxxxxxx>]

For other reasons we stopped using this path for file injection by
default. This bug is sufficiently old that I assume it is no longer in
progress.

** Changed in: nova
       Status: In Progress => Invalid

-- 
You received this bug notification because you are a member of Yahoo!
Engineering Team, which is subscribed to OpenStack Compute (nova).
https://bugs.launchpad.net/bugs/1024586

Title:
  avoid the use of kpartx in file injection

Status in OpenStack Compute (Nova):
  Invalid

Bug description:
  kpartx has various problems...

  1. The git repo on kernel.org is no longer available.

  2. kpartx -l had side effects:
    $ kpartx -l /bin/ls
    $ ls
    text file busy
  To fix you need to run losetup -a to find the assigned loopback device
  and then losetup -d /dev/loop...

  3. On an unconnected loop device we get warnings, but an EXIT_SUCCESS ?
    # kpartx -a /dev/loop1 && echo EXIT_SUCCESS
    read error, sector 0
    llseek error
    llseek error
    llseek error
    EXIT_SUCCESS

  4. Also for a loop device that is connected,
  I get a "failed" warning, but the EXIT_SUCCESS
  is appropriate in that case as the mapped device
  is present and usable
    # kpartx -a /dev/loop0
   /dev/mapper/loop0p1: mknod for loop0p1 failed: File exists

  5. There are issues with qcow2 encoded cirros images
  # qemu-img info cirros-0.3.0-x86_64-disk.img
  image: cirros-0.3.0-x86_64-disk.img
  file format: qcow2
  virtual size: 39M (41126400 bytes)
  disk size: 9.3M
  cluster_size: 65536
  # qemu-nbd -c /dev/nbd15 $PWD/cirros-0.3.0-x86_64-disk.img
  # ls -la /sys/block/nbd15/pid
  -r--r--r--. 1 root root 4096 Jun  8 10:19 /sys/block/nbd15/pid
  # kpartx -a /dev/nbd15
  device-mapper: resume ioctl on nbd15p1 failed: Invalid argument
  create/reload failed on nbd15p1

  6. There was a report that `kpartx -[ad]` were not synchronous
  with the creation/deletion of /dev/mapper/nbdXXpX
  requiring sleep calls to avoid failures.

  The best way to avoid the need for kpartx is to use the
  newer kernel auto partition mapping feature available since kernel 3.2
  and only fallback to kpartx if not exists ...
    '%sp%s' % (self.device, self.partition)
  Note the nbd module must be mounted with param max_part=16 etc.
  so that would need documentation.
  Also we would need to test the same applies for raw loopback images
  as well as nbd

To manage notifications about this bug go to:
https://bugs.launchpad.net/nova/+bug/1024586/+subscriptions