Jerry Amundson writes:
This way, if the Internet goes down at either site, only Internet e-mail
at that site is affected, whereas, currently, Internet downtime creates
many problems (of course).
Crazy? Perhaps, but rsync'ing shouldn't cause any problems because of
the unique file names, and it's --delete option should preserve the
Maildir structure across to the "mirror" server, right? Our main office
only has about 100 employee's, so the T1 bandwidth should suffice...
If one of the lines goes down and everyone switches over to using the
rsync-ed mailboxes on the other server, then when service is restored the
first rsync will obliterate any changes made to the rsync-ed copies of the
mailboxes.
For purposes of providing backup access to mailboxes only, maybe you should
install a cheap cablemodem in each office. Something that takes out a telco
T1 is not likely to affect the cablemodem plant. Even with limited upstream
bandwidth via cable, it should be sufficient for a dozen or so concurrent
users. Furthermore, you can expect a T1 outage to be usually resolved
fairly quickly, so you only need to bear with it for a little while.
Alternative wireless Internet may also be available in some areas.
Or, it's possible that a fractional T1 between the two offices may be
cheaper than a pair of backup low-bandwidth circuits. Except that a backhoe
incident in the immediate neighborhood will likely take out both circuits.