Phoenix Special Mount

General Methodoloy

The host runs a daemon, which monitors specific directories, waiting for commands to appear (via inotify). The host daemon could do such things as restart a VZ, access various mount points etc.

Management.

• /syscmd/scripts holds master scripts.
• /syscmd/<vzid> holds hard-links to the enabled scripts for <vzid>
• <vz-priv>/.syscmd -- monitors by daemon for messages.
• <vz-priv>/syscmd -- RO bind-mount of /syscmd/<vzid>

Sample Run

• `echo "host:/usr/portage" >> /.syscmd/caston.110
  • Effect: provided the host:/usr/portage is enabled from the host, there will be a bind-mount placed from /usr/portage /<vz-private>/usr/portage

Guest Scripts

• caston -- activate all available mounts / approve all mounts.
  • caston _{mount all available/offered mounts}
  • caston 104:/var/tmp _{permit 104 to mount over my /var/tmp}
• castoff -- umount all mounts.
  • castoff _{umount all}
  • castoff /var/tmp _{remove mount on /var/tmp}
  • castoff 104:/var/tmp _{remove mount on /var/tmp}
• castblock -- block any mounts from taking place.
  • castblock _{block anything except what's already mounted}
  • castblock /var/tmp _{prevent ANYTHING from mounting /var/tmp}
• showcast -- list all 'configured mounts'
  • showcast _{reveal active mountpoints.}
  • showcast -a _{reveal ALL available/offered mount points.}
• cast -- share a folder.
  • cast <dir> <vz>
• ucast -- remove a shared folder.
  • ucast <dir> <vz>

Host Scripts

Host Daemon

function

• Monitors active VZ.
  • inotify watch on <vz-private-path>
• Monitors root (/) on VZs w/o /.syscmd
• Monitors /.syscmd on all VZ's where present.

config

• /etc/vzcmd/vzdaemon.conf
• /etc/vzcmd/casts.ini

  [104]
  _accepted = None
  /var/tmp = 103:/var/tmp,105:/_external/var/tmp
  [103]
  _accepted = 104:/var/tmp
  _blocked = None
  _offered = 105:/etc/1337
  [105]
  _blocked = All
  [published]
  104 = /tmp/portage, /etc/skel,/home/magicaluser
  host = /usr/portage(ro),/tmp/portage(ro)