Quorum IP - IBM FlashSystem 

Quorum IP helps IBM FlashSystem clusters running smoothly during network issues or site failures. It prevents split-brain situations by acting as a tie-breaker, deciding which side of the cluster should remain active and continue I/O operations.

The IP Quorum application is Java-based and runs on a separate server, which can be deployed either on-premises or in the cloud, depending on customer requirements. It communicates with the cluster nodes over a standard IP network to maintain system stability.

This design ensures high availability, security, and reliable cluster operation even during failures.

Why quorum IP's ?

To ensure strong security and proper network isolation, Quorum IPs are used. The Quorum IP network is isolated from the management network, which includes the Cluster IP and Service IP.

The management network typically allows multiple ports to remain open to support various administrative and service-related functions, but for Quorum IP only port 1260 is opened.

Quorum IP enables users of Policy based HA to configure a secure network connection between Quorum application and FlashSystem nodes. Additionally, quorum IP’s can be configured on a separate VLAN for more stricter restriction.

Creating Quorum IP
Via GUI

1. Inside "Settings" -> "Quorum IP addresses", Click on "Add Quorum IP", And we can assign Quorum IP's

Via CLI

Quorum Portset

We have introduced a new  "Quorum" type portset that will contain Quorum IP(s) from each node. There will be a new system created default portset and it will  support one IP (IPv4 or IPv6), with or without VLAN, per node.

1. Assign an IP address on the Quorum Portset using the mkip CLI, .

mkip -prefix 24 -portset quorum -node node1 -ip x.x.x.x -port 5 -gw x.x.x.x

2. We can manage Quorum IP using our existing set of CLI's (mkip, chip, rmip, lsip)

Note : Once user has to configured Quorum IP in all the nodes of FlashSystem, they need to generate new quorum app using GUI or mkquorumapp command and deploy the newly created jar file, to the IP quorum host server.

Best Practices

• Configure the Quorum IP's to all the nodes of FlashSystem and provide a separate IP specially for Quorum related work.
• Verify IP configuration and connectivity.
• The IP must be unique across the nodes.
  

FAQs

Can the GUI be accessed using the Quorum IP?

No. The Quorum IP is for quorum app server access only.

How many Quorum IPs can be configured per node?

1 Quorum IP per node

Can the Quorum application run on a virtual machine?

Yes, it can run on a VM, physical server, or cloud instance.

What will happen, when we don't configure Quorum IPs?

IP quorum application connects to nodes via the existing Service IPs.