On Fri, Apr 12, 2002 at 03:01:05PM -0400, Betsy Schwartz wrote: > Using rsync could get sticky. With a simple rsync, no matter how frequently > you sync'ed you would have the problem of messages that came in after the > sync started. Once you failed over to the backup mail server, failing back > to the primary would be complicated by needing to check for messages that > came in after the last sync. Incoming mail would have to be paused, I'd > think. Then, frequent rsync's over a network where different users are > using different POP servers would be a big performance hit. And I don't > think rsync can't tell the difference between a message that came into > machine A since the last sync, and one that was sync'ed from A to B > previously and then deleted on B. And it is a hairier problem if the mail > is in one big spool file. And, then there's IMAP. Hmmm. I have to think > about this, a lot but it almost seems like some sort of staging server is > called for, something that could separate synchronization from POP, making > sure that everything is backed up before the user sees it. Hmm, but how to > then remove the messages that the user has downloaded....
Another approach is one that Software.com/Openwave took with Intermail. They have a journal of all transactions for the mail store, and that journal/log file can be shipped to a hot-recovery site to keep a spare mail store in sync with the master. -Jeff --- Send mail for the `bblisa' mailing list to `[EMAIL PROTECTED]'. Mail administrative requests to `[EMAIL PROTECTED]'.
