Listen voice messages on server A from server B with asterisk

I have RealTime asterisk with 3 servers. In database I hold sippears only and voicemail boxes. Voicemail messages are stored on the system FILE_STORAGE.

Server A and B are for calls and sip registrations and Server C is dundi. Currently everything work fine.. I can call from Server A to Server B. The problem is when I leave message to number who is busy and registered on Server B.. then this number disconnect and register on Server A -> he can't listen the messages because it is stored on Server B..

How can I make any user to be able to listen his messages no matter on which server are?

Solution

You have alot of options, most of each in clustering area.

Simplest options are:

Glusterfs setup on both server, voicemail in glusterfs directory. This one do failover
NFS/samba share on both servers.
mysql master-master replication, use ODBC_STORAGE, put all voicemails in db. This one is recommended if you also want easy access from web interface to your voice files and simple search/lookup/get message. Highly recommended use innodb tables and optimized mysql config.