ferna...@dfcom.com.br wrote:
I´m reading the past topics related to archive and scalability of dovecot,
they are all very interesting. Here, I´m using two dovecot proxies in
front of five storages pairs, and we split the domain´s accounts among
those servers. So, we can share the i/o load and if one server goes down
only few accounts of the domain stops (not all of them).
But, we began to have space problems - and the solution would be insert
more and more storage servers. So I was searching for some archive
solutions (hard links - at S.O level, or some dovecot extension). A friend
told me that he knows an ISP that share even the mailbox of the users
among many servers -
this is very weird and (at same time) very interesting approach. Instead
of put all messages into one maildir and this maildir into one server,
this "maildir" (?) is spplited among many servers - so, if one servers
fails the account is still acessible and they move old/big messages to a
new "cheap" storage - archiving transparently.
Surely, other than the possibility of archiving a copy in a separate location at
delivery time, everything else here is better done by a high-availability
clustered SAN and *not* by an application?
Archival is a valuable thing to have. Being able to, on delivery, deposit a
separate copy elsewhere (without necessarily indexing it etc.) allows for
near-line back-up or storage where legal or corporate regulation require.
(I'm currently doing this using a cron job and a program I've written which
checks to see if there are any new messages in everyone's inbox Maildirs and
then hard-links them into a separate directory structure once a minute. Messages
which disappear from the true inbox are then kept for a further 90 days. This
allows users to recover messages that they may have accidentally deleted from
their inbox.)
Oh, and with reference to the second paragraph... hard links only work on a
single filesystem, not across multiple filesystems or servers.
Steve
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