I have a MariaDB master-slave setup on 2 CentOS 7.0 servers. Today, I extended a LVM volume on the master server (because it was getting full). After extending the partition, I rebooted the server and reconnected the slave to it. All went well and the server appeared to sync any queries run on the master again.
But, in my monitoring (Cacti) I noticed a very "suspicious" freefall in the disk space usage on the slave host.
I am not sure why. Did the slave drop/rotate binlogs when reconnecting to the master maybe? Then again, almost 600GB in binlogs seems insane.
I ran the pt-table-checksum
tool from the Percona Toolkit to verify integrity between the hosts, running this command returns no diffs. So everything seems well, I just can't explain the massive drop in disk space usage, does anybody have an idea?