After installing Virtuozzo 6.0 update 10 , it is not possible to migrate a container if the path to its private area contains symbolic link and it resolves to other location.
~# readlink -f /vz/private/ /pstorage/clustername/private
This is the common setup on the servers with Virtuozzo storage (Pstorage).
The migration operation fails like this:
~# pmigrate c 111 c 10.10.10.10 Connection to destination node (10.10.10.10) is successfully established Moving/copying CT#111 -> CT#111, ,  ... locking 111 External snapshot /pstorage/clustername/private/111/root.hdd/root.hds detected in /vz/private/111/root.hdd Can't move/copy CT#111 -> CT#111, ,  : External snapshot /pstorage/clustername/private/111/root.hdd/root.hds detected in /vz/private/111/root.hdd
~# prlctl migrate 111 10.10.10.10 Migrate the CT 111 10.10.10.10 () firstname.lastname@example.org's password: Failed to migrate the CT: Failed to migrate the Container. An internal error occurred when performing the operation. Try to migrate the Container again. If the problem persists, contact the Parallels support team for assistance.
In order to avoid data corruption under certain circumstances, the check was implemented to ensure that all container's snapshots are located in the same place, inside the container's private area.
However, due to symlinks in the path, the check gives false positive results for containers without snapshots.
The issue was submitted as internal request PSBM-39503.
The issue was permanently fixed in Virtuozzo 6.0 Update 10 Hotfix 1 (6.0.10-3145). Please install pending updates.
Change the default location of the container's private area in the file "/etc/sysconfig/vz" and in the configuration files of container to point to the explicit location.
E.g. if the container's private area is in "/pstorage/clustername/private/", replace "/vz/private/" with this explicit path.