The easiest way to upgrade Dovecot 1.x to 2.0 on RHEL/CentOS 5.

Hi, all.

Just want to show you how easy to upgrade Dovecot-1.x to 2.0 on RHEL/CentOS 5.

Summary

We are going to setup a new virtual machine with RHEL/CentOS 6, so that we have a working config file for Dovecot-2.0. Then simply copy it after we upgraded Dovecot packages.

Note: If you don't want to setup a new virtual machine, we have a sample Dovecot-2.0 config file available for your use: https://bitbucket.org/zhb/iredmail/raw/ … ecot2.conf

Important notes before you start

[+] The latest iRedMail forces clients to use secure connection for POP3 and IMAP services, if you don't want to do this, please check this tutorial: How to allow insecure POP3/IMAP connection

Steps

*) Download Dovecot-2.0 from below URLs:

[+] Dovecot-2.0.x: http://packages.atrpms.net/dist/el5/dovecot-2.0.x/
[+] dovecot-managesieve and dovecot-pigeonhole: http://packages.atrpms.net/dist/el5/dovecot-pigeonhole/

*) Backup Dovecot config file first.

[+] WARNING: Please copy files with '-p' option to keep file owner and permission.
[+] Note: We backup /etc/dovecot.conf, but we don't use it for upgrading at all. it's useful if you want to downgrade from Dovecot-2.0 to 1.x.

# mkdir /root/dovecot-backup/
# cp -p /etc/dovecot.conf /root/dovecot-backup/old.dovecot.conf
# cp -p /etc/dovecot-* /root/dovecot-backup/

*) Setup a virtual machine (VMware/Xen/VirtualBox/KVM/etc), install RHEL/CentOS 6 on it. Then deploy iRedMail. iRedMail will install Dovecot-2.0 for you. Its config files are all placed under /etc/dovecot/. Main config file is /etc/dovecot/dovecot.conf.

Again, If you don't want to setup a new virtual machine, we have a sample Dovecot-2.0 config file available for your use: https://bitbucket.org/zhb/iredmail/raw/ … ecot2.conf

Note: iRedMail doesn't use config files under /etc/dovecot/conf.d/.

[+] Copy /etc/dovecot/dovecot.conf to your iRedMail server which running Dovecot-1.x. assume it's /root/dovecot2.conf.
[+] Now open /root/dovecot2.conf, make sure you have the same values for below parameter as Dovecot-1.x.

# Make sure Dovecot has right owner/permission to store received emails.
mail_uid = 
mail_gid =
first_valid_uid =
last_valid_uid =

# Make sure Dovecot will delivers email to correct mailboxes.
mail_location = maildir:/%Lh/Maildir/:INDEX=/%Lh/Maildir/

# Append this domain name if client gives empty realm (no '@domain.com' part in login username).
auth_default_realm = 

# Make sure per-user sieve filters can be read/write.
sieve_dir = /%Lh/sieve
sieve = /%Lh/sieve/dovecot.sieve

After you sync above parameters in new config file, it's ready to upgrade Dovecot-1.x.

*) Stop Dovecot service and remove RPM packages.

# /etc/init.d/dovecot
# rpm -e dovecot dovecot-managesieve dovecot-pigeonhole

*) Install Dovecot-2.0 you download. it's mentioned above (step 1).

# rpm -ivh dovecot-2.0.xxx dovecot-pigeonhole-xxx dovecot-managesieve-xxx

*) Copy sample config file to /etc/dovecot/:

# cp /root/dovecot2.conf /etc/dovecot/dovecot.conf
# chown root:root /etc/dovecot/dovecot.conf
# chmod 0664 /etc/dovecot/dovecot.conf

*) Restore backup files to /etc/dovecot/. Again, copy files with '-p' option to keep file owner and permission.

# cp -p /root/dovecot-backup/dovecot-* /etc/dovecot/

*) It's now ok to restart Dovecot service and testing:

# /etc/init.d/dovecot restart

Dovecot logs to /var/log/dovecot.log by default, so please send some testing emails and make sure no error occur.

After upgrading

[+] You may want to move /etc/dovecot*.conf (used by Dovecot-1.x) to another place to avoid confusion.