User Guide Home   >   Server Advanced Features   >   Disaster Recovery

When DR features are enabled, you must select one of the following roles for Syncrify server:

• DR-Master:

Machine designated to run as the primary server. Syncrify clients connect to this machine to run backups.

• DR-Slave:

Machine designated to act as a stand-by server. This machine can be made master within a few seconds in case the actual master goes down.

Features

Syncrify server automatically copies the following from a master to slave

• User repositories
• Server configuration
• User configuration - provided an RDBMS is not used
• Reports
• Delete retention records
• Auto upgrade - slave gets upgraded when you upgrade the primary

In simple terms, Syncrify server becomes read-only when it is designated as a DR-Slave.
Following restrictions apply when a server is assigned a role of DR-Slave.

• Backups from Syncrify client are prohibited. Syncrify client should always run their backups to the primary server.
• You cannot upgrade a DR-Slave independently. When the primary gets upgraded, slave will automatically upgrade itself.
• A DR-Slave will inherit branding information from the primary.
• Changes to users or configuration is not allowed.
• Daily reports are not sent.

Prerequisites

Before assigning a DR-Slave rold to a server, ensure the following conditions are met:

• IMPORTANT: DR-Master and DR-Slave should be connected over a fast network. We do not recommend running a DR-Slave across the Internet. In order to maximize scalability, rsync algorithm is not used when transferring files to DR-Slave.
• Both DR-Master and DR-Slave must run on similar operating systems. For example, it is okay to run a DR-Master on Windows 2008 and DR-Slave on Windows 2003. You cannot have DR-SLave on Linux when DR-Master is running on Windows.
• Free disk space must be similar between DR-Master and DR-Slave.
• The folder structure must be identical. This means you should install Syncrify in the same folder. The repository path for every user must be identical as well.

The following steps assume the primary server, which will become DR-Master, is already up and running. You must setup a DR-Slave before configuring DR-Master.

• Setting up DR-Slave
• Install Syncrify server on another machine.
• Complete the initialization procedure after installation. For the time being, you can sign up for it to run in Personal mode.
• Login to the web interface using the admin account.
• Click Configuration and then, Disaster Recvoery.
• Select DR-Slave and Save.


• Setting up DR-Master
• Login to the web interface of your primary server using the admin account.
• Click Configuration and then, Disaster Recovery.
• Select DR-Master.
• Specify the IP Address or host name of the DR-Slave.
• Click Save.


• Switching a DR-Slave to DR-Master

If your primary server goes down, switch a DR-Slave to DR-Master using the following steps:

• Login to the web interface of your DR-Slave server using the admin account.
• Disable disaster recovery completely.
• Have your clients connect to this backup server. There are several ways to switch. The easiest is to have the firewall send Syncrify's inbound traffic to this other machine.

Can I have more than one DR-Slave for one DR-Master?

Yes. The relationship between DR-Master and DR-Slave is one-to-many; meaning one DR-Master can connect to multiple DR-Slaves. However, it is not the other way around. You cannot configure one DR-Slave to replicate more than one DR-Master.


When are files replicated?

A DR-Master will replicate files as soon as a backup is completed or when configuration is modified. Additionally, it also backs up the enter dataset once per day.


Is rsync used when replicating files?

No. The rsync protocol sacrifices CPU and local disk I/O in order to save network traffic. This is the reason why we recommend both DR-Master and DR-Slave to be on a fast network. Although Syncrify will only copy modified files between the two machines, it will copy the file in its entirety.


Do I have to purchase an additional license?

No. DR-Slaves inherit licensing information from DR-Master and therefore, no additional license is required.