Hi, I would need some suggestion for a dovecot based mail infrastructure. Actually, only one server (with dovecot sendmail amavis spamassassin clamav etc etc) is no longer enouth, so I thought I would put on a more complex infrastructure on different servers.
But I do not know a few things. I was thinking about partitioning users on 3-4 servers with dovecot (imap / pop3) and dovecot-lda (no networked filesystem between them) and then configuring 1-2 servers with dovecot director and 1-2 servers for SMTP with postfix. It is not clear how the director will map user -> server to be used and, in a user virtualization context (maybe on MySQL) what is the owner / permissions I should give to home folders where I will store mail
Thank you. Simone.
On 7 Aug 2017, at 10.14, Simone Marx :: Edinet Srl simone@edinet.info wrote:
Hi, I would need some suggestion for a dovecot based mail infrastructure. Actually, only one server (with dovecot sendmail amavis spamassassin clamav etc etc) is no longer enouth, so I thought I would put on a more complex infrastructure on different servers.
But I do not know a few things. I was thinking about partitioning users on 3-4 servers with dovecot (imap / pop3) and dovecot-lda (no networked filesystem between them) and then configuring 1-2 servers with dovecot director and 1-2 servers for SMTP with postfix. It is not clear how the director will map user -> server to be used and, in a user virtualization context (maybe on MySQL) what is the owner / permissions I should give to home folders where I will store mail
TBH, if you really are going to have standalone backends without any shared storage and you are going to bind users to specific backend then you are better off without director layer. Instead you should use dovecot proxies to forward the connections (imap/lmtp) to specific backend from there.
Sami
On Mon, Aug 07, 2017 at 09:14:16AM +0200, Simone Marx :: Edinet Srl wrote:
Hi, I would need some suggestion for a dovecot based mail infrastructure. Actually, only one server (with dovecot sendmail amavis spamassassin clamav etc etc) is no longer enouth, so I thought I would put on a more complex infrastructure on different servers.
Sounds good.
But I do not know a few things. I was thinking about partitioning users on 3-4 servers with dovecot (imap / pop3) and dovecot-lda (no networked filesystem between them) and then configuring 1-2 servers with dovecot director and 1-2 servers for SMTP with postfix.
Sounds a bit less good. If you only have one server now, then partitioning out by function will probably be *much* easier. Everything except dovecot is very easy to spread out across servers, so to take the easy route I would probably keep dovecot where it is, and spread out the other functions on new servers. You can have one or two sendmail servers, two or more AV servers, and add to those as needed. I'll bet that your "not enough" problems are more related to the AV functions than to dovecot.
The disadvantage of that is that it keeps the dovecot server as a SPOF. Are you running virtualized infrastructure? If you are, cool. If you're not, and you won't, then you may want to have dovecot on more servers, but then you do it for the redundancy, not for performance! Make sure you get the rest of the redundancy right. For example, partitioning users across two servers will not give you redundancy, so doing that will not help you unless one dovecot server is not enough to handle the load, and since doing it is a lot of tricky work, I'd certainly postpone doing it until needed.
Last time I did this I set up storage on a SAN and had one box running dovecot and one box as a hot spare for any function in the cluster.
HTH
P.S. BTW... Sendmail?
Hi
Sounds a bit less good. If you only have one server now, then partitioning out by function will probably be *much* easier. Everything except dovecot is very easy to spread out across servers, so to take the easy route I would probably keep dovecot where it is, and spread out the other functions on new servers. You can have one or two sendmail servers, two or more AV servers, and add to those as needed. I'll bet that your "not enough" problems are more related to the AV functions than to dovecot.
It's not completely true. The trend in recent years has seen the increase in the size of the mailboxes as well as their number. It's true what you say, so you partially won, but consider that virtual server provider I will use offers machines with a fixed mix of resources (instance A with 4vCPU/8GB RAM /100GB SDD, B with 6vCPU/16GB RAM /200GB SDD etc), no block storage available, and that I'm actually hitting low disk space with 1.5TB, I will waste vCPU for storage/dovecot instances.
P.S. BTW... Sendmail?
I'm using sendmail but I thought that in an environment like the one proposed was better postfix with virtual users, any suggestions?
Thank you.
Simone.
participants (3)
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Lorens Kockum
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Sami Ketola
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Simone Marx :: Edinet Srl