Yes, we do use pretty much the setup you describe, i.e. rsync push to
backup server, btrfs volume with daily snapshot subvolumes on the
server. This particular setup has been in use for more than two years by
now, and is working well with 8-10 servers (totals for all backed-up
filesystems is about 1.2TiB/2.5M files of varying size; transferred
This sounds exactly as the solution we're using. Only we backup up to a freenas device, using rsync, zfs and it's snapshots. Using 4*6TB WD disks in a raidz2 config. Allowing for two disks to die at the same time without data loss. The freenas gui makes configuring everything simple.
I must say: zfs is absolutely super.