This article explains how to resolve the issue when /var partition is utilizing 100% due to MySQL bin files

This issue will occur If there is a change in MySQL database update in very little time.

For example, here is the update from Engineering on the public PR 1748467 :

The appvisibility polling has been reduced from 15mins to 5mins time interval. So mysql transactions will be happening for every 5 mins in the appvisibility db tables. Having high mysql transactions is an expected one with this change. However, why mysql bin files are not getting deleted and filling up the disk space needs to be checked. I believe, ideally it should get deleted after replication. If its not getting deleted and relying upon the expire days or purging policy to get triggered.

Workaround:

1. Log in to Junos Space Network Management Platform CLI.
2. Edit the /var/chroot/mysql/etc/my.cnf file, to add:

expire_log_days=3

1. Restart MySQL service using the following command:

service mysqld restart

The issue is also fixed in the space hotpatch v1 of 23.1