[Dovecot] Dovecot vs Exim file locking
Hi all:
We're planning to deploy a large e-mail system storing maildirs in a NAS system through NFS. One of the options we're thinking on is using Dovecot+EXIM.
As far as I've read in both project's documentation, both services implement locking allowing multiple servers to access the same maildirs in order to distribute the service load. However, I can't find any information explaining whether both locking mechanisms are compatible, whether any additional configuration is needed both in Dovecot and/or EXIM, or even whether any locking synchronization between both services is needed/recommendable at all.
The only remote clue I've found is that, according to Dovecot docs: "Because Dovecot uses its own non-standard locking (dovecot-uidlist.lock dotlock file), other MUAs accessing the maildir don't support it." (but EXIM is not a MUA, anyway)
Anyhow theoretically MailDir could even be considered free of locking problems, but I'm not sure of the real implications of putting together several Exim and Dovecot installations pointing to the same NFS filesystem.
Any knowledge/experience/link/clue on this would be greatly appreciated.
Thanks in advance,
Daniel Campos
On Sex, 18 Dez 2009, Daniel Campos wrote:
We're planning to deploy a large e-mail system storing maildirs in a NAS system through NFS. One of the options we're thinking on is using Dovecot+EXIM.
As far as I've read in both project's documentation, both services implement locking allowing multiple servers to access the same maildirs in order to distribute the service load. However, I can't find any information explaining whether both locking mechanisms are compatible, whether any additional configuration is needed both in Dovecot and/or EXIM, or even whether any locking synchronization between both services is needed/recommendable at all.
The only remote clue I've found is that, according to Dovecot docs: "Because Dovecot uses its own non-standard locking (dovecot-uidlist.lock dotlock file), other MUAs accessing the maildir don't support it." (but EXIM is not a MUA, anyway)
Anyhow theoretically MailDir could even be considered free of locking problems, but I'm not sure of the real implications of putting together several Exim and Dovecot installations pointing to the same NFS filesystem.
Any knowledge/experience/link/clue on this would be greatly appreciated.
As far as I know, maildir does not require locking.
I used sometime exim + dovecot without problems. Now I use dovecot's
deliver, by doing that you'll certainly have no problems.
-- Genius doesn't work on an assembly line basis. You can't simply say, "Today I will be brilliant." -- Kirk, "The Ultimate Computer", stardate 4731.3
Eduardo M KALINOWSKI eduardo@kalinowski.com.br
On Dec 18, 2009, at 8:41 AM, Daniel Campos wrote:
We're planning to deploy a large e-mail system storing maildirs in a NAS system through NFS. One of the options we're thinking on is using Dovecot+EXIM.
As far as I've read in both project's documentation, both services implement locking allowing multiple servers to access the same maildirs in order to distribute the service load.
Mail deliveries don't require any locks with maildir. But for Dovecot, be sure to read http://wiki.dovecot.org/NFS
Hi Ecuardo,Timo, thanks for your answers!
-----Mensaje original----- De: Timo Sirainen [mailto:tss@iki.fi] Enviado el: viernes, 18 de diciembre de 2009 15:30 Para: Daniel Campos CC: dovecot@dovecot.org Asunto: Re: [Dovecot] Dovecot vs Exim file locking
On Dec 18, 2009, at 8:41 AM, Daniel Campos wrote:
We're planning to deploy a large e-mail system storing maildirs in a NAS system through NFS. One of the options we're thinking on is using Dovecot+EXIM.
As far as I've read in both project's documentation, both services implement locking allowing multiple servers to access the same maildirs in order to distribute the service load.
Mail deliveries don't require any locks with maildir. But for Dovecot, be sure to read http://wiki.dovecot.org/NFS
__________ Informacisn de NOD32, revisisn 4704 (20091220) __________
Este mensaje ha sido analizado con NOD32 antivirus system http://www.nod32.com
Hi,
I am trying to deploy large e-mail system but I will use qmail-ldap on Linux and maildir will be mounted by all backends from Netapp via NFS.
In LDAP, there will be only one mailhost entry. All qmail-ldap backends will have same name and will run dovecot instance. So, all users can access to mailbox from any server in the pool. If I distribute users with different mailhosts and if one mailhost server is down, the users will not able to access their mailbox until fix the problem or change mailhost entry with working one.
But I don't know the NFS issues in my planned setup. Do you think that I will face same NFS locks/problem(OS based) with Netapp NFS?
Thanks in advance.
On Mon, Dec 21, 2009 at 9:15 AM, Daniel Campos dcampos@cesex.com wrote:
Hi Ecuardo,Timo, thanks for your answers!
-----Mensaje original----- De: Timo Sirainen [mailto:tss@iki.fi] Enviado el: viernes, 18 de diciembre de 2009 15:30 Para: Daniel Campos CC: dovecot@dovecot.org Asunto: Re: [Dovecot] Dovecot vs Exim file locking
On Dec 18, 2009, at 8:41 AM, Daniel Campos wrote:
We're planning to deploy a large e-mail system storing maildirs in a NAS system through NFS. One of the options we're thinking on is using Dovecot+EXIM.
As far as I've read in both project's documentation, both services implement locking allowing multiple servers to access the same maildirs in order to distribute the service load.
Mail deliveries don't require any locks with maildir. But for Dovecot, be sure to read http://wiki.dovecot.org/NFS
__________ Informacisn de NOD32, revisisn 4704 (20091220) __________
Este mensaje ha sido analizado con NOD32 antivirus system http://www.nod32.com
participants (4)
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Daniel Campos
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Eduardo M KALINOWSKI
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Ibrahim Harrani
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Timo Sirainen