dovecot - Sep 2010 - Fwd: NFS question

Resent to list, since my previous direct emails to Timo have gone unanswered
I am NOT a member of this list so Timo please reply direct

I do not wish responses from those who are not developers of dovecot, many I
have since had discussions with on another list and spam binned  (abusive
souls like charlie marcus) some for trolling, I seek a definitive answer and
there is only one man who can give this, but I likely was mailing a old
address he doesn't read

---------- Forwarded message ----------
From: Nick Edwards <nick.z.edwards at gmail.com>
Date: Fri, Sep 24, 2010 at 6:15 PM
Subject: NFS question
To: timo at iki.fi


After reading the archives recently on a few threads about NFS I have
concerns
over our plans to move from cyrus to dovecot, we initially discounted
dovecot as
a choice over it, but since dovecot and sieve go well together, I am just
re-capping
everything before we approve move to courier or back to dovecot, having re
read
those threads over a couple of times, am I right in assuming that this
caching
problem, is really only a problem if using imap and the chances of it being
an
issue with pop3 is very rare?
If this is the case, then we certainly would approve move to dovecot.

I note some people who have apparently much larger systems than us,  say
that
they have seen no problems but others say they may have had just not
noticed.

So, if smtp3 delivers to storage MailDir and pop3-1 connects to get mail -
at the same time: no problem just wont see that message until next refresh
at the same time: will see message

if smtp3 and smtp1 deliver at same time there lies the corruption issue?
If so, it will be reindexed at next delivery or pop3?

Just trying to understand where it will be a problem,  we will use postfix
setting of   virtual_transport = dovecot and
dovecot_destination_recipient_limit = 1


We dont allow multiple logins either, we have only intention for one imap
server, to compliment our two pop3's and 4 smtp's.

We intend to use -

pop3_lock_session=yes
maildir_very_dirty_syncs=yes
auth_verbose = yes
auth_cache_size = 512
auth_cache_ttl = 3600
auth_cache_negative_ttl = 0
mail_location = maildir:/var/vmail/%1d/%d/%n/Maildir
mmap_disable = yes
mail_nfs_storage = yes
mail_nfs_index = yes

protocol lda {
        mail_plugins = quota cmusieve
        quota_full_tempfail = yes
        auth_socket_path = /var/run/dovecot/auth-master
}

Also, will this be more of a problem if we use dovecot v1.2 or v2.0 ?
(only examples of configs we have for our move is for v1.2 at present for
debian)

Hope you do not mind me asking this in private, but given how those threads
ended up in personal attacks, I would rather not reignite any fires.

Nick

On 2010-09-29 1:27 AM, Nick Edwards wrote:
> I do not wish responses from those who are not developers of dovecot,
Then you should have spent the few seconds required to browse the PUBLIC
list archives for Timo's current email address - then I wouldn't have
even seen this message and you wouldn't be getting this response.
> many I have since had discussions with on another list and spam
> binned (abusive souls like charlie marcus)
If you consider simply correcting your misunderstanding of how dovecot
works as 'abusive', then, yeah, I guess I'm guilty as charged.
> but I likely was mailing a old address he doesn't read
Like I said - took me all of 10 seconds to determine his current email
address from his most recent posting to this list (he posts daily).

-- 

Best regards,

Charles

On Wed, 2010-09-29 at 15:27 +1000, Nick Edwards wrote:
> To: timo at iki.fi
This has never been my email address. I don't know who it goes to.
> After reading the archives recently on a few threads about NFS I have
> concerns
You've read http://dovecot.org/list/dovecot/2010-August/052188.html
thread?
> over our plans to move from cyrus to dovecot, we initially discounted
> dovecot as
> a choice over it, but since dovecot and sieve go well together, I am just
> re-capping
> everything before we approve move to courier or back to dovecot, having re
> read
> those threads over a couple of times, am I right in assuming that this
> caching
> problem, is really only a problem if using imap and the chances of it being
> an
> issue with pop3 is very rare?
With POP3-only users it should be rare. But if they're using webmail
also that adds IMAP there which makes it less safe. Also with POP3 you
might want to disable indexes anyway and use filename as POP3 UIDL and
then corruption wouldn't matter at all (dovecot-uidlist file updates are
actually pretty pointless then).
> Also, will this be more of a problem if we use dovecot v1.2 or v2.0 ?
They work identically. Although today I made performance improvements to
POP3, and I'll probably still make some more.

Anyway, I can't give you any guarantees. I only know that it's not 100%
safe, but some people with POP3-only/mostly setups have been happy
enough anyway.