Sometime accounts are to big to transfer via the WHM transfer feature.

Below you can find some steps to do so manually 

Log into your server and create a cPanel backup for the account

/scripts/pkgacct <username> <location> backup

<username> refers to the username you want to backup.

<location> is the path to where the backup will be placed (in your case you want to put /backup/cpbackup here).

So backup tells pkgacct that you want to create a backup file.

If you leave this off it creates a cpmove archive. Not sure what the difference is between a cpmove and a backup file, but this tells pkgacct you just want to create a <username>.tar.gz file in <location>.

And after the backup has been completed you can simple move it by pushing it via SCP

here is the tutorial  http://www3.wiredgorilla.com/content/view/322/1/  

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