Resolution

To do this follow the steps below:

1. Upload migration agent and modules to the source server. For example for Parallels Plesk Panel, there are two folders: /usr/local/psa/PMM/agents/shared and /usr/local/psa/PMM/agents/PleskX. Use the command below to copy the Migration Manager:

destination ~# scp -r /usr/local/psa/PMM/agents/shared/* /usr/local/psa/PMM/agents/PleskX/* root@source:/temporary_migration_directory/

2. Login to source server and change to directory /temporary_migration_directory.
Run migration agent (PleskX.pl) with parameter --help to get all available options of the migration agent. Start dumping with options you need. For example:

source ~# cd /temporary_migration_directory
temporary_migration_directory ~# chmod 755 PleskX.pl
temporary_migration_directory ~# ./PleskX.pl --dump-all

3. This will create dump configuration file dump.xml and content dump archives in current directory /temporary_migration_directory.

4. On the destination server create directory /work_dir and copy file dump.xml from /temporary_migration_directory to it.:

source ~# scp /temporary_migration_directory/dump.xml root@destination:/work_dir/

5. On destination Parallels Plesk Panel 8 create subdirectory /work_dir/archives and copy other content dump files to this directory:

source ~# scp -r /temporary_migration_directory/* root@destinationPPP8:/work_dir/archives/

On destination Parallels Plesk Panel 9 dump.xml and all other content files should locate in the same directory. So copy all other files into /work_dir/:

source ~# scp -r /temporary_migration_directory/* root@destinationPPP9:/work_dir/

6. Deploy the data through Parallels Plesk Panel GUI.

Login to Parallels Plesk Panel (PPP) as administrator and change to the Migration Manager page. The page is Server -> Migration Manager in PPP version 8.x and Home -> Migration Manager in PPP version 9.x

Click button "Start a new migration" and choose "Data import" in PPP version 8.x or "Transfer data already processed by the migration agent and located on the local host." in PPP version 9.x.

In version 8.x pay attention for choosing correct Working directory for the data importing, it should the directory where you put the data to be restored (/work_dir).
In version 9.x put location of dump.xml file in the "Migration data file location" field. It should be /work_dir/dump.xml.