You can have Aspera software log to the directory of your choice by modifying the syslog.conf file, located in the /etc/ directory on Linux operating systems.

Add local0.none and local2.none to /var/log/messages.

For example, if you have this:
*.info;mail.none;authpriv.none;cron.none /var/log/messages

Change it to:
*.info;mail.none;authpriv.none;cron.none;local0.none;local2.none
/var/log/messages

Next, forward local0.info and local2.info log messages to your new file. If you want to write to a different file such as /var/log/aspera.log, add this line:
local0.info;local2.info -/var/log/aspera.log

If you would like a separate log file for the ascmd subsystem, you can forward the local2.info to yet another log file (ie: ascmd.log). Here is an example of the new lines you would need to add to your syslog.conf file:
local2.info -/var/log/ascmd.log

Now your ascp messages should appear in /var/log/aspera.log and your ascmd messages should show up in /var/log/ascmd.log instead of /var/log/messages.