SvSAN Witness
Eliminate the risk of split-brain while benefiting from true two node high availability
StorMagic SvSAN’s witness service is the lightweight, incredibly resilient feature that enables genuine high availability between two server nodes. Included in both SvSAN Standard and Advanced Editions, the witness ensures that hardware failure and the threat of downtime can be significantly reduced, while split-brain can be eliminated completely.
White Paper: Explaining the StorMagic SvSAN Witness
Read a more detailed examination of how the SvSAN witness enables 2-node high availability with this white paper which includes requirements, tolerances, testing performance and failure scenarios. Complete the form and continue your learning.
Without a witness, an even-numbered cluster is at risk of split-brain. If a node loses contact with the cluster it becomes isolated, operating independently, and its data becomes inconsistent with the rest of the cluster. When this node is eventually reintroduced to the cluster, these inconsistencies may result in data corruption and potentially even data loss.
The SvSAN witness prevents split-brain scenarios from occurring. It can be sited locally to a cluster, or at a remote location over a WAN link. A single SvSAN witness can provide a quorum service to hundreds of SvSAN clusters. Additionally, it can tolerate significant latency and low bandwidth, allowing it to be located great distances from the clusters it provides quorum service for, even if they are in remote, harsh environments. These attributes make the witness an ideal fit for organizations with many locations where local highly available storage is a requirement at each, such as a nationwide retail chain that uses just 4 witnesses across more than 2000 stores.
“During system testing and automatic reboots, SvSAN recovers and starts synchronizing immediately, and in just 20 minutes, everything is fully fault tolerant again with no manual intervention. We’ve experienced 100% system uptime for six years and counting.”
Bart de Goeij | Asset Management/Maintenance & Operations | Amsterdam Airport Schiphol
"As of today we've had zero issues, no split brain scenarios and I'm confident that I can go on holiday without downtime!"
Ryan Anderson | Manager of IT | CDS Group of Companies