[Lxc-users] lxcpath

[Papp Tamas]

On 02/25/2013 02:56 PM, Serge Hallyn wrote:
>
> Quoting Papp Tamas (tompos at martos.bme.hu):
>> hi Serge and Others,
>>
>> lxc version: 0.9.0.alpha3
>>
>> lxcpath=/data/lxc
>>
>> tank/lxc/ltest on /tank/lxc/ltest type zfs (rw,noatime)
>>
>>
>> # sh -x /usr/bin/lxc-create -n ltest -t ubuntu
>> + . /usr/share/lxc/lxc.functions
>> + globalconf=/etc/lxc/lxc.conf
>> + bindir=/usr/bin
>> + templatedir=/usr/share/lxc/templates
>> + lxcinitdir=/usr/lib/x86_64-linux-gnu
>> + get_default_lxcpath
>> + grep -v ^# /etc/lxc/lxc.conf
>> + grep [ \t]*lxcpath[ \t]*=
>> + awk -F= { print $2 }
>> + lxc_path=/data/lxc
>> + backingstore=_unset
>> + fstype=ext4
>> + fssize=500M
>> + vgname=lxc
>> + custom_rootfs=
>> + [ 4 -gt 0 ]
>> + opt=-n
>> + shift
>> + optarg_check -n ltest
>> + [ -z ltest ]
>> + lxc_name=ltest
>> + shift
>> + [ 2 -gt 0 ]
>> + opt=-t
>> + shift
>> + optarg_check -t ubuntu
>> + [ -z ubuntu ]
>> + lxc_template=ubuntu
>> + shift
>> + [ 0 -gt 0 ]
>> + wantedhelp=0
>> + [ -z /data/lxc ]
>> + [ ! -r /data/lxc ]
>> + [ -z ltest ]
>> + [ -z  ]
>> + lvname=ltest
>> + id -u
>> + [ 0 != 0 ]
>> + [ -n  ]
>> + :
>> + [ -d /data/lxc/ltest ]
>> + basename /usr/bin/lxc-create
>> + echo lxc-create: 'ltest' already exists
>> lxc-create: 'ltest' already exists
>> + exit 1
>>
>>
>>
>> So a new container cannot be created, because the directory already exists, as it's on an own
>> filesystem.
>
> Yes lxcpath does not address the case of wanting to import an existing
> rootfs.  Only the case of wanting to keep the rootfs on a different
> partition.  But you can now keep the container config in
> /data/lxc/ltest/config instead of under /var/lib/lxc/ltest, which
> might keep things (like where the fstab should be) less confused.

I'm not sure, I understand, what you get to point. Or maybe I miss that:)

This is, what I do:

1. I create a partition or zfs volume for the container to keep
2. lxc-create -t ubuntu


What about this small change?

--- /usr/bin/lxc-create.ORIG	2013-03-03 00:38:19.749777404 +0100
+++ /usr/bin/lxc-create	2013-03-03 00:39:17.050725908 +0100
@@ -205,7 +205,7 @@
          ;;
  esac

-if [ -d "$lxc_path/$lxc_name" ]; then
+if [ -d "$lxc_path/$lxc_name/rootfs" ]; then
      echo "$(basename $0): '$lxc_name' already exists" >&2
      exit 1
  fi


Though not perfect at all since it cannot handle the case, when there is a mountpoint inside the 
rootfs (eg. rootfs/var).
But I think with this change it would work way comfortable.


tamas