Upgrading 1.4 to 2.0 while switching server OS as well

I’ve been running UrBackup for almost 2 years now, with the server in a FreeBSD jail (under FreeNAS). That’s required compiling from source. That hasn’t been a big deal, but FreeNAS 9.10 is now making it easier to run a Linux VM, so I’d like to switch to the Linux UrBackup server instead. I’m curious if anyone has any suggestions on the safest way to do that and also switch to UrBackup 2.0 while maintaining my existing backups.

Can I safely switch the server OS from FreeBSD to Linux, or is there anything OS-specific in the storage mechanism or the backup_server.db? I’m guessing I’d first install the Linux UrBackup server in a new VM, then copy over selected files from the FreeBSD jail’s /usr/local/var/urbackup. Looks like it would be at least backup_server.db, clientlist_?.ub, backup_server_settings.db. What about the server_ident.* and server_token.key files? Would it be safe to copy the entire directory over from FreeBSD to Linux?

Also, would it make more sense to try to first install the 1.4.14 UrBackup for Linux, get it working with the existing backup data, then update to 2.0.30? That seems less likely to blow up on me then moving from FreeBSD to Linux and 1.4.14 to 2.0.30 in one step.

There isn’t anything OS specific, so copying the files should be fine. Simply copy all the files. It needs *.db, *.ub, *.priv, *.pub.
The backup storage path should match, otherwise you need to run remove-unknown to fix the symbolic links in existing backups.

I’d do it in one step.

The thing most likely to cause you problems is probably the FreeBSD Linux ABI. But perhaps that way FreeBSD will have file hole punching (fallocate with FALLOC_FL_PUNCH_HOLE).