Quorum Servers Considerations
Enabling or configuring quorum service is a post-install configuration task. Stratus recommends configuring two quorum service computers: a preferred quorum server and an alternate. For an overview of quorum servers, see Quorum Servers.
Quorum service software, if deployed, can be installed on any general-purpose computer or laptop running the Windows operating system with these requirements:
- OS: Windows XP (SP2 or newer), Windows Server 2003, Windows Vista, or Windows 7, or Windows Server 2008; always powered on
- Disk space: 100 MB (minimum)
- NIC: at least one (1)
- Connectivity: Available to the everRun configuration via the management network
To install quorum server software:
- From the Drivers and Tools section of the everRun Enterprise Downloads and Support page at http://www.stratus.com/go/support/everrun, download the quorum server software installer file to the quorum server.
- On the quorum server, double click the installer file.
Note: When upgrading to a more recent version of quorum server software, you do not need to uninstall the previous version.
In addition, consider the following for quorum service best practices:
- Configure two quorum service computers with minimum common networking between the quorum computers and the hosts.
- As installed, protected VMs contact quorum service computers using UDP port 4557. Firewalls must permit everRun-protected VMs to contact quorum service computers using UDP port 4557. (If this port assignment conflicts with your local infrastructure, you can use different port numbers when you configure the quorum servers using the everRun Availability Console.)
- Quorum service computers should not reside on the same site as any host when deploying in a SplitSite. If both preferred and alternate quorum computers fail for a common reason, VMs will gracefully downgrade redundancy, and then continue to operate using one host, pending recovery of a quorum computer. However, if a host and the elected quorum computer fail for a common reason, the VMs running on the surviving server shut themselves down. For additional information about quorum servers and SplitSite configurations, see SplitSite Network Requirements and SplitSite Configurations.
- If the preferred and alternate quorum service computers must reside on a common site, power them from separate AC power sources (phases) or configure them on separate UPS devices.
Related Topics
Physical Machines and Virtual Machines
Configuring Quorum Servers
The everRun Availability Console
Using the everRun Availability Console