Lets say we have 100GB of data stored in MyISAM tables. 90GB will never be changed (archived tables) and 10GB are changed every minute.
-> Backup will lock all tables for ~10 minutes and also replication will have some delay.
I made some modifications to the innobackupex-script (used with parameter --checkfiles) so that it will first copy all tables (~10 Minutes), then lock all tables und recopy only changed tables (10GB) in ~1 Minute.
-> Backup is 10% slower but table-lock is also minimized to 10%
So you only have to save some file-information like ‘date changed’ and ‘filesize’ for every file you copy - and on second copy you simply compare that filesizes and dates on the local server (not as rsync does on the remote side).
I did that for cp and scp (remote-host)… works quite well.