[Dovecot] tags disappear in Thunderbird
We have -
Dovecot 1.0.15 (the default on Debian Lenny stable) Thunderbird 3.1.4
In our installation the Inbox is a mbox and the other folders are maildir.
When we tag messages in Inbox, the tags disappear after a while. In the other folders they stay.
I found two possible solutions suggested -
Set mbox_lazy_writes=no
Convert the Inbox to maildir
What would be the best approach in your opinion?
Would suggest not following the Debian Lenny stable version (1.0.15), but compiling the current stable Dovecot?
Thank you very much, Iv
Iv Ray wrote:
We have -
Dovecot 1.0.15 (the default on Debian Lenny stable) Thunderbird 3.1.4
< snip >
Would suggest not following the Debian Lenny stable version (1.0.15), but compiling the current stable Dovecot?
The Debian backports service can update your version to Dovecot 1.2.13, since you are using Lenny/Stable.
The backports service is described here:
Debian Backports
"The website [1] and the mirror moved to http://backports.debian.org/ and the archive is now available below debian-backports/. Even though we expect the old entries to continue to work for a while, you might still want to update your sources.list entry to:
deb http://backports.debian.org/debian-backports lenny-backports main contrib non-free (careful with the line-wrap, there, include a <sp> before 'main')
or one of the mirrors[2] that do carry the backports archive."
I'm not sure whether a newer version than 1.2.13 runs on Debian Lenny without other new libraries etc, so we, also, would be interested to hear about later versions installed on Lenny. Especially, if existing mail is unaffected (we use Maildir but comment on any mail storage experience would be valuable).
regards, Ron
Iv Ray wrote on 21.09.2010:
Would suggest not following the Debian Lenny stable version (1.0.15), but compiling the current stable Dovecot?
You can also use the automatically built packages from Stephan. They can be found here: http://xi.rename-it.nl/debian/
More informations can be found here: http://wiki.dovecot.org/PrebuiltBinaries#Automatically_Built_Packages
Compiling Dovecot 2.x under Lenny is no problem but the easier way is to use the release from the above source.
Because Dovecot 2.x isn't available for Lenny or the upcoming version "Squeeze" you must use external repositories or compile Dovecot yourself.
I would also use maildir for all mailboxes instead of mbox for inbox...
-- Daniel
Thank you Ron and Daniel.
We tried the mbox_lazy_writes=no option and it seems to work. It was the easiest thing to try.
We will now attempt upgrade to the Dovecot stable and switch the Inbox to maildir.
Thank you for your kind comments.
Iv
On 21.09.2010, at 12:02, Daniel Luttermann wrote:
Iv Ray wrote on 21.09.2010:
Would suggest not following the Debian Lenny stable version (1.0.15), but compiling the current stable Dovecot?
You can also use the automatically built packages from Stephan. They can be found here: http://xi.rename-it.nl/debian/
More informations can be found here: http://wiki.dovecot.org/PrebuiltBinaries#Automatically_Built_Packages
Compiling Dovecot 2.x under Lenny is no problem but the easier way is to use the release from the above source.
Because Dovecot 2.x isn't available for Lenny or the upcoming version "Squeeze" you must use external repositories or compile Dovecot yourself.
I would also use maildir for all mailboxes instead of mbox for inbox...
-- Daniel
Iv Ray put forth on 9/21/2010 5:21 AM:
We will now attempt upgrade to the Dovecot stable and switch the Inbox to maildir.
One thing at a time. Do one or the other first, wait a few days or a week to make sure it is working as expected. Only then perform the other. If you do both simultaneously or in rapid succession, it may make troubleshooting more difficult should something happen to break. If you only make one change at a time you will know what to blame for the breakage.
-- Stan
Daniel Luttermann put forth on 9/21/2010 5:02 AM:
I would also use maildir for all mailboxes instead of mbox for inbox...
Do you have technical justification for this recommendation, or is this merely "personal preference"? If both exist on NFS storage in a Dovecot cluster environment I would tend to agree due to potential locking and caching issues. Regarding local storage I don't see how there would be much, if any, of an operational difference, performance or otherwise.
I'm not calling BS here, but asking for solid technical reasoning behind the recommendation.
-- Stan
On 21/09/2010 11:39, Stan Hoeppner wrote:
Daniel Luttermann put forth on 9/21/2010 5:02 AM:
I would also use maildir for all mailboxes instead of mbox for inbox...
Do you have technical justification for this recommendation, or is this merely "personal preference"? If both exist on NFS storage in a Dovecot cluster environment I would tend to agree due to potential locking and caching issues. Regarding local storage I don't see how there would be much, if any, of an operational difference, performance or otherwise.
I'm not calling BS here, but asking for solid technical reasoning behind the recommendation.
Reduced complexity.
One storage format is simpler, and really (think Occam's razor) should be the starting point for negotiations.
If anyone has to come up with an argument it is why someone should use two storage formats instead of one.
To some people that may sound specious, but I suspect that is probably just a manifestation of the underestimation of the cost of complexity.
Bill
Stan Hoeppner wrote on 21.09.2010:
Daniel Luttermann put forth on 9/21/2010 5:02 AM:
I would also use maildir for all mailboxes instead of mbox for inbox...
Do you have technical justification for this recommendation, or is this merely "personal preference"? If both exist on NFS storage in a Dovecot cluster environment I would tend to agree due to potential locking and caching issues. Regarding local storage I don't see how there would be much, if any, of an operational difference, performance or otherwise.
I'm not calling BS here, but asking for solid technical reasoning behind the recommendation.
Nothing technical - personal preference and as William wrote: reduced compexity.
I don't see any benefit in the use of two different mailbox formats so I would tend to use only one of the available mailbox formats at once. Are there situations where two different formats will perform better or work more reliable? Why not use mdbox instead of a combination of mbox and maildir?
-- Daniel
Stan Hoeppner wrote:
Daniel Luttermann put forth on 9/21/2010 5:02 AM:
I would also use maildir for all mailboxes instead of mbox for inbox...
Do you have technical justification for this recommendation, or is this merely "personal preference"?
Could I offer our reasoning for choosing Maildir?
I made the decision that we would use Maildir because I was worried about the effect of loss of a single file. As I understood it, mbox stores all the messages in single file and, if the file was corrupted and couldn't be recovered for any reason, then we'd lost a whole lot of messages. We back up to alternate machines, anyway, but backup systems fail to secure us when or if a file is deleted mistakenly, for example, and not quickly noticed, say.
We hold corporate emails dealing both with clients, and with statutory bodies. In our country, there are legal obligations on corporate entities to interact with statutory authorities (tax, registration, etc) electronically, so loss of email messages may contribute to compliance defaults which can carry penalties.
We also had to convert our historic emails from a windows platform - this was maybe 2 or 3 years ago now. The script, that we used, converted to Maildir slightly more competently - I think one date or other in the message was better converted, but I cannot quite remember, now. I only remember that converting to Maildir was slightly easier or better than to mbox.
So our reasons are:
(1) Risk aversion - we simply do not want the hassle of losing many, many emails just through a file failure
(2) Easier conversion from other formats, in our case
Interested to hear others' reasoning. Incidentally, even if we become sufficiently risk-accommodating to use V2.x, I would prefer to stay with Maildir because I don't really want to 'risk' transferring/recoding/reformatting all the email messages etc. We need to avoid risks that are, simply, avoidable.
regards, Ron
Could I offer our reasoning for choosing Maildir?
I made the decision that we would use Maildir because I was worried about the effect of loss of a single file. As I understood it, mbox stores all the messages in single file and, if the file was corrupted and couldn't be recovered for any reason, then we'd lost a whole lot of messages. I do not agree to this view; there are two possible scenarios what could happen:
a) filesystem corruption - with maildir you probably end up with an ugly mess of unconnected directories, while for mbox you need to find the one file (per folder) for user x.
b) file is corrupt (altered by two processes, bad sector, filesystem corruption on file level) - the mbox file can be repaired easily, if you want, by hand. For maildir you need to find the affected parts of the directory structure, probably more than one file will be affected as dovecot needs to open many nodes simultaneously
In all these cases it is best to have a current backup (which is easy to say but hard to achieve with classical backup methods for a mail folder). In either case you could spend hours on fitting pieces together and even then you are not sure that nothing is missing.
That said, we use maildir and mbox formats for several hundred mailaccounts in different setups and never had a real corruption problem, besides one issue with badly formatted From: lines several years ago.
Jakob Curdes
On Tue, 2010-09-21 at 13:56 +0200, Jakob Curdes wrote:
b) file is corrupt (altered by two processes, bad sector, filesystem corruption on file level) - the mbox file can be repaired easily, if you want, by hand.
With mbox data is moved in-place within the file while doing expunge. A crash in the middle of expunge corrupts the mbox file, although no data will actually be lost with the way Dovecot does it (but you may have duplicate mails and one of the mails could be split into two parts inside the file). A power loss during expunge could be worse and maybe lose data, depending on OS/filesystem.
With maildir a crash will never lose or corrupt anything. A power loss also won't corrupt anything, only (maybe) lose some changes. With filesystem corruption anything can happen of course..
b) file is corrupt (altered by two processes, bad sector, filesystem corruption on file level) - the mbox file can be repaired easily, if you want, by hand.
With mbox data is moved in-place within the file while doing expunge. A crash in the middle of expunge corrupts the mbox file, although no data will actually be lost with the way Dovecot does it (but you may have duplicate mails and one of the mails could be split into two parts inside the file). A power loss during expunge could be worse and maybe lose data, depending on OS/filesystem.
With maildir a crash will never lose or corrupt anything. A power loss also won't corrupt anything, only (maybe) lose some changes. With filesystem corruption anything can happen of course..
Since years I am impressed with the stability of our dovecot installations even under high load situations etc. So we should probably put it that way:
a) corruption is unlikely with both formats b) if you have (filesystem) corruption, you need a good backup ...
JC
participants (7)
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Daniel Luttermann
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Iv Ray
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Jakob Curdes
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Ron Leach
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Stan Hoeppner
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Timo Sirainen
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William Blunn