I have configured the warm standby using WAL FILES and DRBD. The wal files are generated as server A. I am using DRBD to replicate these wal files between server A and server B. The DRBD service is running as Primary on Server A and secondary on Server B. The wal_files are written to the server B, but there is a drawback for DRBD. The filesystme needs to be unmounted on the server B (where DRBD is running secondary role).
So recovery is not countinuous.(file systme is unmounted). To start the recovery, i need to change the DRBD role to primary on server B. After that i have to mount the filesystem. Once i mount the filesystem, the recovery process starts.
Is there any way in which i need not switch secondary/primary role for DRBD on server B? Is there any way in which i can have the file system mounted on server B, running DRBD secondary role?
How else can i replicate the wal_files? ( i don't want to user common file system ,,, NFS,,, etc.)?
Another thing which i want to ask is that if we are generating archives every 1 minute. then what happens to the data which was written to the server A after 35 seconds after the last wal file generation.(server A crashes).
Since this data has not been archived (it was supposed to archive after 1 minute), do i think that this is the loss of data in a server A crash as this 35 second data has not been written to the archived logs and neither has been transported to server B?