-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Carlos E. R. wrote:
The Tuesday 2008-09-23 at 17:40 +0200, Hylton Conacher (ZR1HPC) wrote:
I guess the way around that is to have two rsync jobs being one for the mail directories and the other for only the document directories?
Or more frequent backups. Those are the cases where raid does not help: both copies of the document wold be broken.
Restoring email queues is not so simple, anyway, maybe you could end resending mail already sent. I think that often it is better to leave the email as lost and resend from the client if needed. This is a situation for which RAID is better, IMO.
A different thing would be a pop/imap server. What would be different?
A sending smtp server does not stores many emails, they are sent as soon as possible. There is almost no point in backup.
A receiving server can store millions of emails.
I ask as it is actually a one person IMAP Dovecot, Postfix,SpamAssassin, Procamil mailserver store I aim to setup. The main purpose of the mail server is to lose as little email, if any email, at all. How can I ensure that no received mail since the last mirror/backup is not lost? Resending email already sent is fine, losing email already received is unacceptable as I will not know who to ask to resend?
Then the alternative is to store every email, as soon as it arrives, on two disks or servers. Notice that, as both are running continuosly, any of them could break as often as the other.
-- Cheers, Carlos E. R.
This is where procmail has it uses... a procmail recipe to forward incoming mail to a mail location or secondary mail server should have a good chance of duplicating the majority of incoming mail. However, it should also be noted *no* backup system will be guaranteed to be 100%, it is more of the decision of how close to that 100% one can reliably get. This is a basic cost benefit analysis, weighing the costs of the backup regime against costs of either loosing or recovering any damaged data, YMMV. (Using RAID in itself is *not* really a backup mechanism, it provides performance and continuity of service but that is a different issue). Email by its nature presents special problems, the dynamic nature of the data structure makes it highly probable that things will be missed during backup (unless you shutdown the mail system, backup the data and restart, data gaps are inevitable... and for most multi-user scenarios such a backup regime would be unacceptable and also probably impracticable). As any backup regime is only as good as its restore mechanism, and restoring email can be highly problematic, people can come to their own conclusions. BTW Anyone who claims that they have never lost data, is probably being rather naive. They have lost data but they just do not know it (yet), and if they did not know it they probably did not need it anyway :-) - -- ============================================================================== I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone. Bjarne Stroustrup ============================================================================== -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkjZ84wACgkQasN0sSnLmgKxnACfZZVSkPugz+VKTM5I3qsK4ByL fXIAoOInR2VDsmaCwu6AVnm63MSOE9fX =UaE2 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org