My general principle for every server is to have at least two full backups – one onsite, and one offsite. I believe freepbx merits the same backup strategy.
It appears as if the recommended way to create a backup is to install freepbx on a spare workstation, upgrade all modules to the latest version, and then restore an existing backup to that spare workstation (Best way to backup entire FreePBX 6.12.65/CentOS 6.5 server?). (I discovered the hard way that if you do not first upgrade all modules prior to doing the restore, the resulting configuration may be invalid, requiring you reinstall freepbx and start over.)
This is somewhat time consuming if you wish to create two backup disks. But even this approach does not give you an exact clone of the freepbx hard disk. Comparing the output of yum list installed shows that the installed packages on the two systems do not match. And there may be other locally installed items such as scripts that are not part of the backup.
I looked at rsync as a possible approach to clone the hard disk, but since freepbx uses the LVM file system, and since I have not discovered any way to simultaneously mount two hard disks containing the same LVM Volume Groups (as would be the case with a clone of the hard disk), I can not find any way to make rsync work. (Perhaps it would be possible to create a clone of the freepbx hard disk using rsync to a different workstation – if so, this would be an acceptable solution.)
So is there a good way to simply and reliably create multiple clones of the freepbx hard disk? Note that I need to be able to do this without shutting down freepbx during the process. I understand, and am willing to accept the possibility that cloning the hard disk in a running system may result in inconsistencies – for example, discrepancies between the contents of voice mail and the contents of the CDR records.
Thanks for any recommendations.