[Bug 861504] [NEW] nova-compute-lxc limited by available nbd devices to 16

[Scott Moser]

Public bug reported:

nova has 'FLAGS.max_nbd_devices' :
   flags.DEFINE_integer('max_nbd_devices', 16,
                     'maximum number of possible nbd devices')

However, 
a.) that doesn't really tell you why you care about this number, even though it effectively limits the number of lxc instances you can run at a single time, as each one uses a nbd device.
b.) it does not modify in any way the number that the system can allocate.
   Ie, we would need to change the module parameter 'nbds_max' to nbd.ko.

Perhaps nova-compute-lxc should install a file into /etc/modprobe.d that increases number, ie:
 # /etc/modprobe.d/nova-compute-lxc.conf
 options nbd  nbds_max=256

And also set the FLAGS.max_nbd_devices in its nova-compute.conf.


Note, one sucky thing, is that without killing or at least stopping all instances, you wouldn't be able to change the module parameter to increase this number.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: nova-compute-lxc 2011.3-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-12.19-server 3.0.4
Uname: Linux 3.0.0-12-server x86_64
ApportVersion: 1.23-0ubuntu1
Architecture: amd64
Date: Wed Sep 28 11:14:28 2011
NovaConf: Error: [Errno 13] Permission denied: '/etc/nova/nova.conf'
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_US:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: nova
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: nova
     Importance: Undecided
         Status: New

** Affects: nova (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug oneiric

-- 
You received this bug notification because you are a member of Ubuntu
Server Team, which is subscribed to nova in Ubuntu.
https://bugs.launchpad.net/bugs/861504

Title:
  nova-compute-lxc limited by available nbd devices to 16

To manage notifications about this bug go to:
https://bugs.launchpad.net/nova/+bug/861504/+subscriptions