Hi Eduardo,
Since I few day I try to setup this config 2, but I've really problem with the NFS.
We come from Google Apps :) I several people on the hospital have large mailbox. For example 96000 mails in the INBOX folder, when I do "ls" that is quick for display mail, but with dovecot... I need wait 1 minuts the first time and after display the amount of mail it's quick.
We don't have NetAPP, we've Dell Equallogic with SATA2 7200rpm, gigabits ports. The Equallogic it's just for store email, and index file.
My config:
Dell Equallogic |-> VMWare ESXI (iscsi mount in VMware with VMWare VMFS 5 format 4To) |--> Mounted as slave disk on a VM Ubuntu and exported with this options "(rw,no_subtree_check,all_squash,anonuid=1000,anongid=1000,async)" and formated as ReiserFS (I've read it's the best for many small files). |---> My 2 Dovecot Backend mount the NFS (fstab) to my previous VM with this options "nfs defaults 0 0" |----> Mail it's stored in MailDir format "mail_location = maildir:%h"
When I go on Roundcube with a mailbox who I've 96000 in the INBOX "cur" folder, the first time I need 1 minutes waiting. The second time it's a little more quick 10 seconds... But when I go back again (after a few hours) it's slow again... And we'are just 5 users at the moment for test...
I've not setup director for the moment I try first dovecot on my lab befor add director and move mailbox from Google...
Have you recommandation for tune or make NFS more quickly, because with Google it's really fast (ok it's google) but if we move to a more slow system, the user on the hospital would no be happy. I've try many config, but no really success for have a fast NFS, I don't know if the problem it's VMWARE or if the problem it's just my NFS options.
I'm not pettry good with linux, I'm most good with Windows server, I'm not a good man Google, Microsoft, I know it's devil for every linux sysadmin :)
Thanks, Nathan
----- Mail original ----- De: "Eduardo Ramos" eduardo@freedominterface.org À: dovecot@dovecot.org Envoyé: Jeudi 24 Juillet 2014 14:01:33 Objet: Re: Multiple servers and NFS
Hi Richard,
You can use one or more instances of Dovecot on the same machine, as you can see here (http://wiki2.dovecot.org/RunningDovecot) "Running Multiple Invocations of Dovecot".
The problem with DNS round-robind is that if you server goes down, DNS continues resolving for it. I would recommend use some balancer like LVS+keepalived.
Consider that multi layer solution:
| LVS + keepalived | | LVS + keepalived |
| |-------------- -------------- | Director 1 | | Director 2 |
| |----------------- ----------------- | IMAP/POP/LMTP | | IMAP/POP/LMTP | | Backend | | Backend |
\ /
\ /
\ ------------ /
-------| NetAPP |---------
------------Remember, directors and backends could run on the same machine. I have a lab running that way. Maybe I can help you deploy. On 07/23/2014 07:23 PM, Richard Hector wrote:
Hi all,
For some reason, I didn't go to http://wiki2.dovecot.org/NFS until now, and I'm starting to get worried ...
The plan was to have multple servers (MXes) receiving mail, and delivering via LMTP to multiple backend dovecot servers (with amavis in front of dovecot; LMTP both sides). Then we'd have multiple servers for clients to use IMAP or POP3.
This is more or less how the system already works, except with Courier IMAP, and postfix on the backends, delivering to maildirs with procmail.
But with the recommendation to use the Director for both IMAP/POP3 and LMTP - that starts to sound like I need a whole bunch more servers to run Directors and proxies, and even then it might not be a good idea to have different servers running lmtp and imap/pop.
One possible mitigating point is that our 'load balancing' is DNS round-robin, so a given client will probably stick with a single imap/pop server anyway, but if the user has multiple clients (desktop/mobile etc) then they may still hit different servers.
Can someone clarify best practice for a setup needing multiple servers for load balancing and redundancy?
Is Courier already likely to have been suffering these problems?
Oh, the NFS server is a NetApp Filer, if that matters.
I'm using dovecot 2.2.9 from debian wheezy backports, in order to get the quota policy daemon support.
Thanks, Richard