Upgrading to 3.8


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.

1. Preparation

Things to consider before you begin:

Versions to upgrade from

Before upgrading to 3.8, your deployment should be running one of:

  • 3.2.10 (or later),

  • 3.4.4 (or later), or

  • 3.6.0 (or later)

If your existing deployment predates these releases, you should first upgrade to one of these versions, let it run for a while, resolve any issues that come up, and only then upgrade to 3.8.

3.2.x prior to 3.2.10, 3.4.x prior to 3.4.4, and all 3.0.x and 2.x releases have inconsistencies in their storage of an optional metadata field (mailbox uniqueids). This was not previously a problem due to the field being optional.

Architectural changes in 3.6 and later make mailbox uniqueids required for almost all operations. If these are inconsistent or missing, the upgrade may not succeed, and the failure may be difficult to recover from.

3.2.10 and 3.4.4 contain changes that detect, report, and fix up missing or inconsistent mailbox uniqueids, allowing for a safer upgrade to 3.6 and later.

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 v3.8.

Storage changes

In 3.6 and later, mailboxes and user metadata directories are organised on disk by UUID rather than by mailbox name.

At startup (or when you first run the updated ctl_cyrusdb -r manually), ctl_cyrusdb(8) will upgrade mailboxes.db to accommodate both old-style and new-style storage, if it didn't already.

By default, new top-level mailboxes will be created in the new style. Mailboxes that already exist in the old style will remain in the old style until you convert them with relocate_by_id(8). New mailboxes below the top level will be created in the same style as their parent mailbox.

The new cyr_ls(8) tool can be used to examine the on-disk contents of a given mailbox name. mbpath(8) can be used to find where on disk a given mailbox and its metadata are.

If you want new top level mailboxes to be created in the old style, you can enable the mailbox_legacy_dirs imapd.conf(5) option, which defaults to off. With this turned on, you may still use relocate_by_id to convert them to the new style.

Since 3.6, sieve scripts are stored in the '#sieve' mailbox (configurable with the sieve_folder imapd.conf(5) option). No manual steps are necessary for upgrade: Cyrus recognises the old style storage and will convert to the new style automatically as necessary.

JMAP/CalDAV changes

Previous versions of Cyrus determined the JMAP CalendarEvent privacy of an iCalendar VEVENT by the CLASS property. As of 3.8, this now gets determined by the newly introduced X-JMAP-PRIVACY property, but the CalDAV indexes may already have entries for the old mapping and need to be upgraded.

Sites that use JMAP should upgrade their CalDAV database index by calling the newly introduced JMAP method Admin/rewriteCalendarEventPrivacy. This method:

  • requires the https://cyrusimap.org/ns/jmap/admin request capability

  • must be called as an admin user (regular user calls are rejected)

  • takes the optional userIds argument, whis is a JSON array of userids to migrate. In absence of this argument, all users are migrated

Site that do not use JMAP should upgrade their CalDAV database by

  • calling DELETE FROM ical_objs WHERE comp_flags >= 1024; on a user's dav.db

  • followed by calling dav_reconstruct for that user

Sieve changes

Cyrus 3.8 no longer supports creating scripts with the deprecated imapflags capability and mark / unmark actions.

Existing Sieve bytecode compiled with mark and unmark will continue to execute (they will be translated to addflag / removeflag "\Flagged").

Any software which generates Sieve scripts will no longer be able to require "imapflags" or use mark or unmark, and should instead require "imap4flags" and use addflag / removeflag "\Flagged".

How are you planning on upgrading?

Ideally, you will do a sandboxed test installation of 3.8 using a snapshot of your existing data before you switch off your existing installation. The rest of the instructions are assuming a sandboxed 3.8 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 3.8 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. 3.8 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 v3.8 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 3.8 Cyrus

Download the release 3.8 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 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 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.

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 3.8 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.

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 3.8 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

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 3.8 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 3.5, you can use 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 3.8 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 3.8 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 3.8 installation.


If you've disabled 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

There were fixes and improvements to caching and search indexing in 3.6. If you are upgrading to 3.8 from something earlier than 3.6, you should consider running reconstruct(8) across all mailboxes to rebuild caches, and squatter(8) to rebuild search indexes. This will probably take a long time, so you may wish to only do it per-mailbox as inconsistencies are discovered. However, if you have been running a 3.5 development version, you should make sure to do this for all mailboxes, due to bugs that were introduced and then fixed during 3.5 development.

9. Do you want any new features?

3.8 comes with many lovely new features. Consider which ones you want to enable. Check the 3.8 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 wish to use XFER to transfer mailboxes from an existing backend to your new 3.8 backend, you should first upgrade your existing backends to 3.6.1, 3.4.5, 3.2.11, or 3.0.18. These releases contain a patch such that XFER will correctly recognise 3.8 and later destinations. Without this patch, XFER will not recognise 3.8, and will downgrade mailboxes to the oldest supported format (losing metadata) in transit.

If your existing backends are 2.4 or 2.5, there are equivalent patches for recognising 3.8+ on the cyrus-imapd-2.4 and cyrus-imapd-2.5 git branches, but these are not in any released version.