[Users] mysqldump exceeding limits

[Joan]

Hi, in the virtual I'm running inside openvz everytime I do the daily
backup of the database it exceeds the limits of othersockbuf
The limits I set up are pretty high, so everything is ok for normal usage.
But as soon as I do "mysqldump -l -B db_name--add-drop-table -u
debian-sys-maint -ppassword > backup.sql"
The counters start growing, even the database is not over 12M

            othersockbuf                 4608              2255872
         2472008             47102365                  155

I tried setting net_buffer_length but nothing changes.
Any idea how can I limit the resources for mysqldump so it doesn't
wake me everynight?