How to backup and restore only differential data on restored full backed up database


I am migrating my 3Tb of mysql Innodb database for OS upgrade and Mysql upgrade (mysql 5.6 - mysql 8.0)

My stakeholder wants this migrated with zero or less than 1 hour application downtime.

Any idea, how can I achieve it?

Hi Supriya,

Taking a physical backup on 5.6 and restoring on 8.0 is not a good idea.

If you were running on 5.7 you could potentially create a 8.0 replica, restore the backup and do the switch over. But 5.6 source and 8.0 replica is not fully supported.

In terms of differential restore, that is done by taking a full backup and a subsequent that will copy only InnoDB LSN pages higher than the last copied from full backup -

Are you doing the OS upgrade in-place (same machine) or are you provisioning a new server?

In case of inplace, take a backup, upgrade the binaries to 5.7, run mysql_upgrade, then upgrade the binaries again to 8.0.