[Dovecot] distributed mdbox

[James Devine]

On Fri, Mar 23, 2012 at 7:39 AM, <list at airstreamcomm.net> wrote:

> On Wed, 21 Mar 2012 09:56:12 -0600, James Devine <fxmulder at gmail.com>
> wrote:
> > Anyone know how to setup dovecot with mdbox so that it can be used
> through
> > shared storage from multiple hosts?  I've setup a gluster volume and am
> > sharing it between 2 test clients.  I'm using postfix/dovecot LDA for
> > delivery and I'm using postal to send mail between 40 users.  In doing
> > this, I'm seeing these errors in the logs
> >
> > Mar 21 09:36:29 test-gluster-client2 dovecot: lda(testuser34): Error:
> Fixed
> > index file /mnt/testuser34/mdbox/storage/dovecot.map.index:
> messages_count
> > 272 -> 271
> > Mar 21 09:36:30 test-gluster-client2 dovecot: lda(testuser28): Error:
> Log
> > synchronization error at seq=4,offset=3768 for
> > /mnt/testuser28/mdbox/storage/dovecot.map.index: Append with UID 516,
> but
> > next_uid = 517
> > Mar 21 09:36:30 test-gluster-client2 dovecot: lda(testuser28): Error:
> Log
> > synchronization error at seq=4,offset=4220 for
> > /mnt/testuser28/mdbox/storage/dovecot.map.index: Extension record update
> > for invalid uid=517
> > Mar 21 09:36:30 test-gluster-client2 dovecot: lda(testuser28): Error:
> Log
> > synchronization error at seq=4,offset=5088 for
> > /mnt/testuser28/mdbox/storage/dovecot.map.index: Extension record update
> > for invalid uid=517
> > Mar 21 09:36:30 test-gluster-client2 dovecot: lda(testuser28): Warning:
> > fscking index file /mnt/testuser28/mdbox/storage/dovecot.map.index
> > Mar 21 09:36:30 test-gluster-client2 dovecot: lda(testuser34): Warning:
> > fscking index file /mnt/testuser34/mdbox/storage/dovecot.map.index
> >
> >
> > This is my dovecot config currently:
> >
> > jdevine at test-gluster-client2:~> dovecot -n
> > # 2.0.13: /etc/dovecot/dovecot.conf
> > # OS: Linux 3.0.0-13-server x86_64 Ubuntu 11.10
> > lock_method = dotlock
> > mail_fsync = always
> > mail_location = mdbox:~/mdbox
> > mail_nfs_index = yes
> > mail_nfs_storage = yes
> > mmap_disable = yes
> > passdb {
> >   driver = pam
> > }
> > protocols = " imap"
> > ssl_cert = </etc/ssl/certs/dovecot.pem
> > ssl_key = </etc/ssl/private/dovecot.pem
> > userdb {
> >   driver = passwd
> > }
>
> I was able to get dovecot working across a gluster cluster a few weeks ago
> and it worked just fine.  I would recommend using the native gluster mount
> option (need to install gluster software on clients), and using distributed
> replicated as your replication mechanism.  If you're running two gluster
> servers you should have a replica count of two with distributed replicated.
> You should test first to make sure you can create a file in both mounts
> and see it from every mount point in the cluster, as well as interact with
> it.  It's also very important to make sure your servers are running with
> synchronized clocks from an NTP server.  Very bad things happen to a
> (dovecot or gluster) cluster out of sync with NTP.
>
> What storage method are you using?  I'm able to produce errors within
seconds of starting postal with more than one thread