Many companies nowadays are heavily dependent on IT for everyday operations, and as such, the availability and uptime of these systems is critically important. Loss of service equates to loss of productivity which, depending on the severity, can have a huge impact on an organization.
Adding high availability to a business’s infrastructure is like adding in an insurance policy, protecting the organization from disruptive downtime. When one node fails or is taken offline, the others remain operational, enabling employees to keep working.
Businesses that require high availability in their applications can design their storage infrastructure in such a way as to create redundancy and eliminate single points of failure. However, in order to properly mitigate against failures and the threat of downtime in two node, shared storage clusters, an additional element is required – the “witness.”
The StorMagic SvSAN Witness:
StorMagic SvSAN is a virtual SAN solution that creates highly available storage across two nodes or more. SvSAN’s ability to provide highly available shared storage on a minimum of just two nodes is a key differentiator, and is made possible by the use of its lightweight witness.
The SvSAN witness prevents split-brain scenarios from occurring in two node SvSAN clusters by regularly checking the state of each node in the cluster. The only data passing between the witness and the SvSAN nodes is the ‘heartbeat’ – the witness is not in the data path. This allows it to tolerate significant latency and low bandwidth, and can therefore be located great distances from the clusters it provides quorum service for, even if they are in remote, harsh environments.