An Asterisk PBX usually requires very little disk space. One of the few exceptions is for voicemail and recordings storage. If a customers VPS runs out of disk space you can pretty much guarantee that the space is being used by recordings.
The easiest way to either delete or mass archive the recordings is via SCP. This works over the SSH port (22) and you use the root/ssh login details that were provided in the welcome e-mail.
If you’re a Windows user then there a nice, simple, free application called WinSCP – http://winscp.net/eng/index.php
Just enter your VPS IP address and the root username and password –
and then browse to /var/spool/asterisk/monitor where the recordings are stored –
from there you can either delete the “.wav” files directly or move them off your VPS and on to your PC