I have a question:
What is the best, easiest and safest way to move a customer account with several domains (not the whole server!) from one server to another?
Both servers have Plesk 8.1 installed.
The best way of migrating domains from one host to another is using Migration Manager.
You can find the Migration Manager tool in the "Server" control panel under "Services". Given, as you said, that both hosts are running the same version of Plesk you are not likely to encounter any problems.
You can find decent (and helpful) documentation which describes the usage of this tool at:
http://download1.swsoft.com/Plesk/Plesk8.3/Doc/en-US/plesk-8.3-unix-administrators-guide/index.htm
Note: this applies to 8.3, but AFAIK almost everything applies equally to 8.1.
Note: Migration Manager documentation is
also available within your own Plesk control panel environment. Once you're
in the migration manager tool, clicking "Help" in the left side navigation column takes you context-specific help. For once "the manual" is useful and definitely gives you enough data to set up and execute a migration.
If you've never used Migration Manager before, perhaps this tip might be of some use:
Before you attempt to migrate live user data, create a test site - with some www data, a mysql db, few domain aliases, a subdomain or two, and a few mail accounts - on the source (the machine you want to move accounts OFF. Then, on the target box (where you want to move the data TO) fire up migration manager and pull the test site across in order to become accustomed to the way the tool works.
Once you're satisfied that everything works as you expected, then set up live migration and pull one live site across. If you're happy with the outcome, then check off a number of sites, start the migration and go grab a cup of coffee.
Migration Manager can also handle pulling sites off other control panel boxes (CPanel etc etc) although this writer has never had reason to use those capabilities.
Other Notes:
You might wish to read back some of the Migration Manager posts in the Plesk 8.1 forums which can be viewed
here
Migration Manager
does work as advertised, but reading issues that some users have experienced, and recommendations from others on how to solve those issues, might be helpful if - like this writer - you're a "documentation hog".
Hopefully, this is sufficient information to get you on the road to happy domain migration.
Good Luck!
Regards & HTH,
/porky