How To Install & Configure Zimbra High Availability (HA)

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In the previous articles, i’ve been explain how to install and configure Zimbra on CentOS 6 or CentOS 7, how to install and configure online failover/failback on CentOS 6 using Heartbeat and how to install and configure data replication on CentOS 6 using DRBD. All above guidance could be combined to get Zimbra High Availability. For online failover/failback, you could using Heartbeat. For data replication, you could using DRBD. Heartbeat + DRBD will produce High Availability (HA). The following is guidance to configure Zimbra HA

Step by step to configure Zimbra HA

For the Linux systems, i am using CentOS 6 64 Bit. For easy understanding, this is my information system

# Server 1
Hostname   : node1
Domain     :
IP Address :

# Server 2
Hostname   : node2
Domain     :
IP Address :

# Alias IP
Hostname   : mail
Domain     :
IP Address :

Alias IP will be used for access clients/users. This alias IP will be configured online failover

# install Zimbra on CentOS 6 on all nodes (node1 and node2) as described at this link : How To Install Zimbra 8.6 on CentOS 6. Please note some information below

– Please change name of each nodes refers into when installing Zimbra

– Set IP address of each nodes refers into include DNS and /etc/hosts

# Stop Zimbra and DNS services on all nodes (node1 and node2)

su - zimbra -c "zmcontrol stop"
service named stop
chkconfig zimbra off
chkconfig named off

# After installed Zimbra, install and configure Heartbeat on all nodes (node1 and node2) as described at this link : How To Configure Online Failover/Failback on CentOS 6 Using Heartbeat

# After installed Heartbeat and online failover/failback working fine, then install DRBD for data replication on all nodes (node1 and node2) as described at this link : How To Configure Data Replication/Synchronize on CentOS 6 Using DRBD

# Testing data replication DRBD that has been worked : Testing Data Replication/Synchronize on DRBD

# After DRBD has been worked, copy file/folder /opt/zimbra into DRBD devices.

Do the following command only at node1

– Rysnc Zimbra

drbdadm primary r0
mount /dev/drbd0 /mnt/tmp
rsync -avP --exclude=data.mdb /opt/ /mnt/tmp

data.mdb will be huge if copied by rsync so that take a long time. For the tricks, use cp for copy data.mdb to DRBD devices 😀

– Copy data.mdb

cp /opt/zimbra/data/ldap/mdb/db/data.mdb /mnt/tmp/zimbra/data/ldap/mdb/db/data.mdb
chown zimbra.zimbra /mnt/tmp/zimbra/data/ldap/mdb/db/data.mdb

# Umount DRBD devices after rsync file/folder Zimbra at node1

umount /dev/drbd0

# Move folder /opt existing to another folder, do the following command on all nodes (node1 and node2)

mv /opt /backup­opt
mkdir /opt

# Configure /etc/hosts and dns records on all nodes (node1 and node2)

vi /etc/hosts

so that like below       localhost   node1   node2    mail
vi /var/named/

change IP address of mail so that refers into IP See the following example

@       IN SOA (
                                        0       ; serial
                                        1D      ; refresh
                                        1H      ; retry
                                        1W      ; expire
                                        3H )    ; minimum
@       IN      NS
@       IN      MX      0
ns1     IN      A
mail    IN      A

# Configure file /etc/ha.d/haresources on all nodes (node1 and node2)

vi /etc/ha.d/haresources

so that like below IPaddr:: drbddisk::r0 Filesystem::/dev/drbd0::/opt::ext3 named zimbra

# Stop service Heartbeat on node2 and then node1

service heartbeat stop

# Start service Heartbeat on node1 and then node2

service heartbeat start


– Failover

After Zimbra running well on node1, please stop service Heartbeat on node1 or force off machine

service heartbeat stop

All services that taken over by Heartbeat will automatically stopped and taken over by node2. How long node2 can start all services worked again, depends how long start services (named and zimbra)

– Failback

Please start again service Heartbeat on node1 or power on machine

service heartbeat start

All running services on node2 will automatically stopped and taken over by node1

Hooray, finally you could build Zimbra HA with DRBD+Heartbeat

For log information about HA process, you can see at /var/log/ha-log

Good luck and hopefully useful 😀


  1. Halo mas imanudin, nama saya Dekri, mau bertanya :
    – Jika server nya berbeda data center dan pastinya berbeda ip address, itu bagaimana ya mas?
    – Selain menggunakan Heartbeat, pacemaker dan DRBD apakah ada software HA lainya ya mas?

    1. Hi mas Dekri,
      – Bisa komunikasi langsung menggunakan IP public mas. Untuk DRBD ataupun untuk Heartbeat nya
      – Dibagian Heartbeat, bisa diganti ucast nya menjadi IP public lawannya
      – Untuk software HA yang lain, saya belum tahu lagi mas

  2. halo, sya alvian, saat sya lakukan mount /dev/drbd0 /opt, direktori zimbranya malah hilang dan sya tidak bisa mengakses zimbranya, salahnya dimana ya…., trimaksih….

    1. Hi mas Alvian,
      Folder nya tidak hilang. Melainkan diganti dengan device drbd yang di mounting. Coba drbd nya mount dulu ke folder lain dan salin seluruh isi /opt/zimbra ke folder hasil mounting DRBD. Bisa dilihat pada bagian ini “– Rysnc Zimbra”

  3. halo mas iman,, waktu penginstalan zimbranya apakah di node ke dua install seperti biasa atau dummy instalation ya_./ -s), dan waktu mengintsall apakah file /optnya perlu di mount dlu k DRBD

    need help for my homework :))

  4. Hai mas aku mau nanya,, aku cluster dan penginstalan sudah selesai, tapi dalam beberapa menit clusternya down dengan log seperti ini
    ResourceManager(default)[93104]: 2019/09/06_03:18:00 ERROR: Return code 1 from /etc/init.d/zimbra
    ResourceManager(default)[93104]: 2019/09/06_03:18:00 CRIT: Giving up resources due to failure of zimbra
    ResourceManager(default)[93104]: 2019/09/06_03:18:00 info: Releasing resource group: vn-zmb-cltr-01-uph IPaddr:: drbddisk::r0 Filesystem::/dev/drbd0::/opt::ext3 zimbra
    ResourceManager(default)[93104]: 2019/09/06_03:18:00 info: Running /etc/init.d/zimbra stop
    Mungkin bsa dbantu mas??

  5. Hi,
    I am using Zimbra mail server with 250 accounts. and I have forwarding of emails accounts to a single account.
    now user didn’t get mails timely due to queues of mails on single account. around 2000 mail stuck in ques.
    please help me out on this. or give solution.

  6. Hey Imanudin, how are you doing ?

    I have one issue while setting up zimbra HA cluster.
    Please find the scenario below.

    I have one server in cloud and another in inhouse. Now what i am going to configure is , setting up two servers with same version of zimbra installation and DRBD setup. Can you please tell me how can i setup virtual ip for inhouse and cloud server ?


    1. Hello,
      1. For your case, you do not need to configure virtual IP
      2. You can create single name on DNS refer to 2 IP public. 1 inhouse IP and 1 IP on the cloud
      3. Or you can create load balancer with haproxy and save in the cloud.

      1. do you mean if we got 2 IP public, how to configure ip set on haresources? what i mean is what ip do i need to set there

        1. Hi Erwin Alifiansyah,
          You can exclude IP on haresources. Only Bind and Zimbra services that handled by haresources

  7. Hi
    After i move /opt to /backup­opt. how am i suppose to start zimbra again?

    “service zimbra start
    warning: cannot change directory to /opt/zimbra: No such file or directory”

      1. Thank you for the response Ahmed. i Noticed after i replaced keepalived with heartbeat 🙂 (heartbeat is end of life in Rhel7 / centos 7 )

        If i want to change something in zimbra do i have to unmount it again and move to opt og are there a way to access su – zimbra

  8. Hello Iman,
    Thanks for work you’ve done for us 🙂

    do you have similar guides (HA, failover) for Zimbra 8.8.15 on Centos 7? =P

  9. HI Iman,

    I had some queries related to PTR records, all the mail servers requires rDNS reords ( PTR ) so in this case if iam creating a server in this private ip internal environment how this will work?

    1. Hi Vishal,
      If you sending email to outside, email will known from public IP. Even use private IP. How to know your public IP, you can check with this command

        1. Use keepalived and conntrackd to replace heartbeat or use pacemaker if that’s an option for you to get virtually any system in HA, you can customize the form conntrackd to trigger any extra actions you might need while monitoring your services with 0 downtime on failover.

  10. Hi,

    Let me know if this method works on Zimbra 9 and Zimbra 10 latest versions installed on the Ubuntu 20 servers.

    Also, let me know what things are needed to get a Zimbra server with High availability in a production environment. No official documentation is available on this.

    I posted these questions on the Zimbra support panel and they responded with two words “Not Possible”.
    1. Possibilities to upgrade mail servers from Zimbra 9 to Zimbra 10 without downtime.
    2. Possibilities for applying Zimbra patch installations on production mail servers without downtime.
    3. Possibilities of High Availability in Zimbra.

    1. Hello Mallu,

      1. Is not possible (upgrade inplace)
      2. Is not possible. After perform patching, sometime need restart for apply patch
      3. Possible. You can use infrastructure method like VMware HA, Proxmox HA, or DRBD+Heartbeat/Pacemaker

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