On Sat, Jul 17, 2010 at 6:29 AM, Daniel Luttermann daniel@dlutt.de wrote:

Hi,

I'm testing Dovecot 2.0rc2 with mdbox mail format and I'm not sure what this exactly means:

http://wiki2.dovecot.org/MailboxFormat/dbox

Quote from wiki page:

===== Expunging a message only decreases the message's refcount. The space is later freed in "purge" step. This may be done automatically within the session or later in a nightly cronjob when there's less disk I/O.

So this means that even if a user deletes a mail the space gets only freed if I run "doveadm purge" manually or an user requests this over his mail client?

When the expunge plugin is used the deleted mails are stored in a special mailbox in the users mailbox so it's needed to use the expire plugin too if this should be done automatically?

Is it recommend to run "doveadm purge" periodically if mdbox is used?

Btw: when I try to run

doveadm -Dv expunge -u testuser@dlutt.de mailbox Trash savedbefore 30d

for example I get such an error:

doveadm(root): Debug: Loading modules from directory: /usr/lib/dovecot/modules doveadm(root): Debug: Module loaded: /usr/lib/dovecot/modules/lib01_acl_plugin.so doveadm(root): Debug: Loading modules from directory: /usr/lib/dovecot/modules/doveadm doveadm(root): Error: dlopen(/usr/lib/dovecot/modules/doveadm/lib10_doveadm_expire_plugin.so) failed: /usr/lib/dovecot/modules/doveadm/lib10_doveadm_expire_plugin.so: undefined symbol: expire_set_lookup doveadm(root): Error: dlopen(/usr/lib/dovecot/modules/doveadm/lib10_doveadm_quota_plugin.so) failed: /usr/lib/dovecot/modules/doveadm/lib10_doveadm_quota_plugin.so: undefined symbol: quota_user_module

Plugin expire or expunge is not currently enabled in Dovecot's config.

Thanks for any hints.

Daniel

I was curious about that as well but had already posted a million questions yesterday =P

What is the default mailbox file size (the m* files?), what actually happens when a message is delivered, when is a new file created, when a user deletes a single mail what happens, or if they delete multiple mails, if a users client does the move to trash then mark as deleted then purge, what happens inside? There was mention of no file truncating, so does that mean if a user deletes mails, and they are in 3 different mail storage files, that those messages are written to 3 new (or existing with free space?) mail storage files and the old ones just sit around using space?

And if you never run a purge or expunge script, will your data store just keep growing, is there no self cleanup? With maildir, you delete a message and the file goes away.

I guess if someone had time to write a slightly more detailed explanation of how mdbox works than what is on the wiki that would be cool. Also maybe a "if you run mdbox, you are going to want to know this and that, and do this and this and this"