I have planed to use master-slave setup and make nightly backups (just coping data) from slave node to 3rd node.
As I understand in master-slave mode it is impossible to read data from slave node? So the question is... what will happened if I will use master-master setup without cluster fs, and will use one of master just as read-only to make backups of it and writes will occur only to second master.
On top of setup will be NFS exports and iSCSI.
Will it work? Maybe there will be some problems...?