Upgrading to 3.2


This guide assumes that you are familiar and comfortable with administration of a Cyrus installation, and system administration in general.

It assumes you are installing from source or tarball. If you want to install from package, use the upgrade instructions from the package provider.


For those upgrading from 2.3.X; newer releases of Cyrus IMAP will use significantly more memory per selected mailbox. This is not an error or bug; it’s a feature. The newer code is holding more data and metadata in memory for purposes of faster access to more of the mailbox. This is not a memory leak.

1. Preparation

Things to consider before you begin:

Installation from tarball

You will need to install from our packaged tarball. We provide a full list of libraries that Debian requires, but we aren’t able to test all platforms: you may find you need to install additional or different libraries to support v3.2.

How are you planning on upgrading?

Ideally, you will do a sandboxed test installation of 3.2 using a snapshot of your existing data before you switch off your existing installation. The rest of the instructions are assuming a sandboxed 3.2 installation.

Upgrade by replicating

If you’re familiar with replication, and your current installation is 2.4 or newer, you can set up your existing installation to replicate data to a new 3.2 installation and failover to the new installation when you’re ready. The replication protocol has been kept backwards compatible.

If your old installation contains mailboxes or messages that are older than 2.4, they may not have GUID fields in their indexes (index version too old), or they may have their GUID field set to zero. 3.2 will not accept message replications without valid matching GUIDs, so you need to fix this on your old installation first.

You can check for affected mailboxes by examining the output from the mbexamine(8) tool:

  • mailboxes that report a ‘Minor Version:’ less than 10 will need to have their index upgraded using reconstruct(8) with the -V <version> parameter to be at least 10.

  • mailboxes containing messages that report ‘GUID:0’ will need to have their GUIDs recalculated using reconstruct(8) with the -G parameter.

If you have a large amount of data, these reconstructs will take a long time, so it’s better to identify the mailboxes needing attention and target them specifically. But if you have a small amount of data, it might be less work to just reconstruct -G -V max everything.

Upgrade in place

If you are upgrading in place, you will need to shut down Cyrus entirely while you install the new package. If your old installation was using Berkeley DB format databases, you will need to convert or upgrade the databases before you upgrade. Cyrus v3.2 does not support Berkeley DB at all.


If you are upgrading from Cyrus version 2.5 or earlier, and your system is configured with the following combination in imapd.conf(5):

fulldirhash: yes
hashimapspool: either yes or no
unixhierarchysep: yes

then you will not be able to upgrade-in-place. This is due to a change in how directory hashes are calculated for users whose localpart contains a dot, which was introduced in 3.0.0. After an in-place upgrade, Cyrus will not be able to find these users’ metadata and/or mailboxes.

If you have this configuration, you will need to upgrade by replicating, not in place.

Do What As Who?

Since the various files, databases, directories, etc. used by Cyrus must be readable and writable as the cyrus user, please make sure to always perform Cyrus commands as the cyrus user, and not as root. In our documentation, we will always reference Cyrus commands in this form – cyr_info(8) – before using examples of them, so you’ll know that those commands must be run as the cyrus user.

Doing so in most systems is as simple as using either the su or sudo commands, like so:

su cyrus -c "/usr/local/bin/cyr_info conf-lint -C /etc/imapd.conf -M /etc/cyrus.conf"
sudo -u cyrus /usr/local/bin/cyr_info conf-lint -C /etc/imapd.conf -M /etc/cyrus.conf

In this document, however, there are also several command examples which should or must be run as root. These are always standard *nix commands, such as rsync or scp.

We strongly recommend that you read this entire document before upgrading.

2. Install new 3.2 Cyrus

Download the release 3.2 package tarball.

Fetch the libraries for your platform. The full list (including all optional packages) for Debian is:

sudo apt-get install -y autoconf automake autotools-dev bash-completion bison build-essential comerr-dev \
debhelper flex g++ git gperf groff heimdal-dev libbsd-resource-perl libclone-perl libconfig-inifiles-perl \
libcunit1-dev libdatetime-perl libdb-dev libdigest-sha-perl libencode-imaputf7-perl libfile-chdir-perl \
libglib2.0-dev libical-dev libio-socket-inet6-perl libio-stringy-perl libjansson-dev libldap2-dev \
libmysqlclient-dev libnet-server-perl libnews-nntpclient-perl libpam0g-dev libpcre2-dev libsasl2-dev \
libsnmp-dev libsqlite3-dev libssl-dev libtest-unit-perl libtool libunix-syslog-perl liburi-perl \
libxapian-dev libxml-generator-perl libxml-xpath-perl libxml2-dev libwrap0-dev libzephyr-dev lsb-base \
net-tools perl php-cli php-curl pkg-config po-debconf tcl-dev \
transfig uuid-dev vim wamerican wget xutils-dev zlib1g-dev sasl2-bin rsyslog sudo acl telnet

If you’re on another platform and can provide the list of dependencies, please let us know via a GitHub issue or documentation pull request or send mail to the developer list.

Follow the general install instructions.


It’s best to ensure your new Cyrus will not start up automatically if your server restarts in the middle of the upgrade.

How this is best achieved will depend upon your OS and distro, but may involve something like systemctl disable cyrus-imapd or update-rc.d cyrus-imapd disable

3. Shut down existing Cyrus

Shut down your existing Cyrus installation with its init script or whatever method you normally use.

This is necessary to guarantee a clean data snapshot.

4. Backup and Copy existing data

We recommend backing up all your data before continuing.

(You do already have a backup strategy in place, right? Once you’re on 3.2, you can consider using the experimental backup tools.)

Copy all of this to the new instance, using rsync or similar tools.


Cyrus keeps its data and databases in various locations, some of which may be tailored by your configuration. Please consult File & Directory Locations for guidance on where data lives in your current installation.

For example, to copy from an existing Debian or Ubuntu installation using their standard locations, you might execute this series of commands on the new server (where “oldimap” is the name of the old server):

rsync -aHv oldimap:/var/lib/cyrus/. /var/lib/cyrus/.
rsync -aHv oldimap:/var/spool/cyrus/. /var/spool/cyrus/.

You don’t need to copy the following databases as Cyrus 3.2 will recreate these for you automatically:

  • duplicate delivery (deliver.db),

  • TLS cache (tls_sessions.db),

  • PTS cache (ptscache.db),

  • STATUS cache (statuscache.db).


You may wish to consider relocating these four databases to ephemeral storage, such as /run/cyrus (Debian/Ubuntu) or /var/run/cyrus or whatever suitable tmpfs is provided on your distro. It will place less IO load on your disks and run faster.


Please be warned that some packages place tasks such as tlsprune (tls_prune(8)) in the START{} stanza of cyrus.conf(5). This will cause a startup problem if the tls_sessions_db is not present. The solution to this is to remove the tlsprune task from START{} and schedule it in EVENTS{}, further down.

5. Copy config files and update

Again, check the locations on your specific installation. For example, on FreeBSD systems, the configuration files imapd.conf(5) and cyrus.conf(5) are in /usr/local/etc, rather than /etc/. Run this command on the old server:

scp /etc/cyrus.conf /etc/imapd.conf newimap:/etc/

Using the cyr_info(8) command, check to see if your imapd.conf file contains any deprecated options. Run this command on the new server:

cyr_info conf-lint -C <path to imapd.conf> -M <path to cyrus.conf>

You need to provide both imapd.conf and cyrus.conf so that conf-lint knows the names of all your services and can check service-specific overrides.

To check your entire system’s configuration you can use the conf-all action. This command takes all the system defaults, along with anything you have provided overrides for in your config files:

cyr_info conf-all -C <path to imapd.conf> -M <path to cyrus.conf>

Important config options: unixhierarchysep: and altnamespace: defaults in imapd.conf(5) changed in 3.0, which will affect you if you are upgrading to 3.2 from something earlier than 3.0. Implications are outlined in the Note in User Namespace Mode and Switching the Alternative Namespace. Please also see “Sieve Scripts,” below.

  • unixhierarchysep: on

  • altnamespace: on


If your installation is using groups, don’t turn reverseacls: on. Reverseacl support only works well for sites without groups.

In cyrus.conf(5) move idled from the START section to the DAEMON section.

6. Upgrade specific items

  • Special-Use flags

    If your 2.4 imapd.conf(5) made use of the xlist-XX directive(s), you can convert these to per-user special-use annotations in your new install with the cvt_xlist_specialuse(8) tool


Berkeley db format no longer supported since 3.0

If you have any databases using Berkeley db, they’ll need to be converted to skiplist or flat in your existing installation. And then optionally converted to whatever final format you’d like in your 3.2 installation.

Databases potentially affected: mailboxes, annotations, conversations, quotas.

On old install, prior to migration:

cvt_cyrusdb /<configdirectory>mailboxes.db berkeley /tmp/new-mailboxes.db skiplist

If you don’t want to use flat or skiplist for 3.2, you can use the new 3.2 cvt_cyrusdb(8) to swap to new format:

cvt_cyrusdb /tmp/new-mailboxes.db skiplist /<configdirectory>/mailboxes.db <new file format>


The cvt_cyrusdb(8) command does not accept relative paths.

7. Start new 3.2 Cyrus and verify

sudo ./master/master -d

Check /var/log/syslog for errors so you can quickly understand potential problems.

When you’re satisfied version 3.2 is running and can see all its data correctly, start the new Cyrus up with your regular init script.

If something has gone wrong, contact us on the mailing list. You can revert to backups and keep processing mail using your old version until you’re able to finish your 3.2 installation.


If you’ve disable your system startup scripts, as recommended in step 2, remember to re-enable them. Use something like systemctl enable cyrus-imapd or update-rc.d cyrus-imapd enable

8. Reconstruct databases and cache

The following steps can each take a long time, so we recommend running them one at a time (to reduce locking contention and high I/O load).

To upgrade all the mailboxes to the latest version. This will take hours, possibly days.

reconstruct -V max

New configuration: if turning on conversations, you need to create conversations.db for each user. (This is required for jmap).:

ctl_conversationsdb -b -r

To check (and correct) quota usage:

quota -f

If you’ve been using CalDAV/CardDAV/all of the DAV from earlier releases, then the user.dav databases need to be reconstructed due to format changes.:

dav_reconstruct -a

If you are upgrading from 3.0, and have the reverseacls feature enabled in imapd.conf(5), you may need to regenerate the data it uses (which is stored in mailboxes.db). This is automatically regenerated at startup by ctl_cyrusdb -r if the reverseacls setting has changed. So, to force a regeneration:

  1. Shut down Cyrus

  2. Change reverseacls to 0 in imapd.conf(5)

  3. Run ctl_cyrusdb(8) with the -r switch (or just start Cyrus, assuming your cyrus.conf(5) contains a ctl_cyrusdb -r entry in the START section). The old RACL entries will be removed

  4. (If you started Cyrus, shut it down again)

  5. Change reverseacls back to 1

  6. Start up Cyrus (or run ctl_cyrusdb -r). The RACL entries will be rebuilt

9. Do you want any new features?

3.2 comes with many lovely new features. Consider which ones you want to enable. Check the 3.2 release notes for the full list.

10. Upgrade complete

Your upgrade is complete, congratulations!

Special note for Murder configurations

If you upgrade murder frontends before you upgrade all the backends, they may advertise features to clients which the backends don’t support, which will cause the commands to fail when they are proxied to the backend.

Generally accepted wisdom when upgrading a Murder configuration is to upgrade all your back end servers first. This can be done one at a time.

Upgrade your mupdate master and front ends last.

If you are upgrading from 2.4, and wish to use XFER to transfer your mailboxes to your new 3.2 server, please consider first upgrading your 2.4 setup to version 2.4.19 or later. Earlier versions of 2.4 do not correctly recognise the 2.5 and later mailbox versions, and will downgrade mailboxes (losing metadata) in transit. 2.4.19 and later versions correctly recognise 2.5 and later servers, and will not downgrade mailbox versions in transit.