SYNC_CLIENT(8)                    Cyrus IMAP                    SYNC_CLIENT(8)

       sync_client - Cyrus IMAP documentation

       Client side of the synchronization (replication) engine

       sync_client [ -v ] [ -l ] [ -L ] [ -z ] [ -C config-file ] [ -S server-name ]
           [ -f input-file ] [ -F shutdown_file ] [ -w wait_interval ]
           [ -t timeout ] [ -d delay ] [ -r ] [ -n channel ] [ -u ] [ -m ]
           [ -p partition ] [ -A ] [ -s ] [ -O ] objects...

       sync_client is the client side of the replication system.  It runs on
       the client (master) system and connects to the target (replica) system
       and generates an appropriate sequence of transactions to synchronize
       the replica system with the master system.

       sync_client reads its configuration options out of the imapd.conf(5)
       file unless specified otherwise by -C.

       -C config-file
              Use the specified configuration file config-file rather than the
              default imapd.conf(5).

       -A     All users mode.  Sync every user on the server to the replica
              (doesn't do non-user mailboxes at all... this could be
              considered a bug and maybe it should do those mailboxes

       -d delay
              Minimum delay between replication runs in rolling replication
              mode.  Larger values provide better efficiency as transactions
              can be merged. Smaller values mean that the replica system is
              more up to date and that you don't end up with large blocks of
              replication transactions as a single group. Default: 3 seconds.

       -f input-file
              In mailbox or user replication mode: provides list of users or
              mailboxes to replicate.  In rolling replication mode, specifies
              an alternate log file (sync_client will exit after processing
              the log file).

       -F shutdown-file
              Rolling replication checks for this file at the end of each
              replication cycle and shuts down if it is present. Used to
              request a nice clean shutdown at the first convenient point. The
              file is removed on shutdown. Overrides sync_shutdown_file option
              in imapd.conf(5).

       -l     Verbose logging mode.

       -L     Perform only local mailbox operations (do not do mupdate
              operations).  This feature was introduced in version 3.0.

       -m     Mailbox mode.  Remaining arguments are list of mailboxes which
              should be replicated.

       -n channel
              Use the named channel for rolling replication mode.  If multiple
              channels are specified in sync_log_channels then use one of
              them.  This option is probably best combined with -S to connect
              to a different server with each channel.

       -o     Only attempt to connect to the backend server once rather than
              waiting up to 1000 seconds before giving up.

       -O     No copyback mode. Replication will stop if the replica reports a
              CRC error, rather than doing a full mailbox sync. Useful if
              moving users to a new server, where you don't want any errors to
              cause the source servers to change the account.

       -p partition
              In mailbox or user replication mode: provides the name of the
              partition on the replica to which the mailboxes/users should be

       -r     Rolling (repeat) replication mode. Pick up a list of actions
              recorded by the lmtpd(8), imapd(8), pop3d(8) and nntpd(8)
              daemons from the file specified in sync_log_file. Repeat until
              sync_shutdown_file appears.

       -s     Sieve mode.  Remaining arguments are list of users whose Sieve
              files should be replicated. Principally used for debugging
              purposes: not exposed to sync_client(8).

       -S servername
              Tells sync_client with which server to communicate.  Overrides
              the sync_host configuration option.

       -t timeout
              Timeout for single replication run in rolling replication.
              sync_client will negotiate a restart after this many seconds.
              Default: 600 seconds

       -u     User mode.  Remaining arguments are list of users who should be

       -v     Verbose mode.  Use twice (-v -v) to log all protocol traffic to

       -w interval
              Wait this long before starting. This option is typically used so
              that we can attach a debugger to one end of the replication
              system or the other.

       -z     Require compression.  The replication protocol will always try
              to enable deflate compression if both ends support it.  Set this
              flag when you want to abort if compression is not available.

       On a replication master, the following would be added to the START
       section of cyrus.conf(5):

          syncclient              cmd="/usr/lib/cyrus/bin/sync_client -r"

       [NB: More examples needed]

       The -L feature, local updates only, was added in version 3.0.


       sync_server(8), cyrus.conf(5), imapd.conf(5), master(8)

       The Cyrus Team, David Carter (, Ken Murchison
       (, Nic Bernstein (Onlight)

       1993-2017, The Cyrus Team

3.0.13                         December 16, 2019                SYNC_CLIENT(8)