Como mencionado no meu comentário acima, o Rsync pode ser uma opção. Outra opção que poderia ser benéfica e servir outros propósitos também é investir no Windows Home Server 2011 (US $ 50). Ele fará um backup noturno dos computadores conectados a ele e poderá ser restaurado de qualquer ponto. Eu uso isso para o computador dos meus pais (remoto). O backup inicial levou de 12 a 24 horas para cada computador transferir por uma WAN. Agora, cada computador faz o backup em 30 minutos a 1 hora, dependendo do seu uso naquele dia. O arquivo PST do meu pai tem cerca de 23 GB.
Fonte: link
Over year ago I posted a question: Does rysnc always copy entire Outlook file? (link)
I now have some data from a backup installation that uses rsync. The data is based on about 1000 backups by 123 users. While rsync works quite well backing up regular files, PST files were a potential source of concern in this application since some were quite large and would get updated by Outlook every time they were opened, even if no changes were made to them. The data indicates that rsync handles even large PST files quite well.
General overview: 123 users are backing up their files on demand to a central Ubuntu server with a quad-core processor, over a 100M/1G LAN. There is quite a mix of different file types - this discussion is limited to PST files. Total PST files per user vary in size from 271KB to 40GB.
Observations: 1) After the initial backup of PST files, subsequent PST backups typically complete twice as fast.
2) The rule-of-thumb for backup times seems to be about 45 seconds to one minute per GB, depending on server load.
3) Changed PST files are reconstructed on the server rather than transmitted over the LAN. This results is a) higher CPU utilization on the server, b) lower CPU utilization on the PC, c) much lower load on the network.
4) Some comparisons of LAN traffic for initial vs. subsequent backups
Initial Subsequent Pct Days
17.0GB: 122.6MB 0.8% 1
12.4GB: 140.1MB 1.2% 4
4.4GB: 32.4MB 0.7% 9
2.0GB: 6.0MB 0.3% 1
3.5GB: 1.5MB 0.04% 1
6.3GB: 2.6MB 0.4% 6
5) Some averages: Wall time per GB: 1m7s CPU time per GB: 0m32s CPU load: 47% (server) Average PST files per user: 4.2GB Average time to backup: 4m21s Equivalent Mb/sec: 128 (if whole file were sent over LAN) Actual Mb/sec: 3.2
6) Performance over slow link (DSL connection): For user with 1.8GB of PST files, the initial backup took 5h21m20s. The subsequent backup completed in 3m56s. This dramatic improvement is where rsync works best (WAN) although it also seems to offer significant improvement in a LAN environment.