Currently zabbix creates new ssh connection for each check, this may result in quite high overhead and system load as well as fill server logs with useless entries. Say we have 20 monitors with 30secs interval, this will give us 40 new ssh connections every minute, 144000 a day. While using persistent connection we could just have roughly 1 connection per hour or less.

On my server I have almost two thousand entries in /var/log/secure and /var/log/wtmp every day.