There are mainly 3 different categories of resources, i.e. On-Off, On-only and Persistent. Under these categories, there are many resources depending upon their usage. In this article we will focus on Proxy and Phantom resources and will tell you what is the basic difference between Proxy and Phantom resources in VCS.
You must be knowing Veritas Cluster Server is now called Infoscale Availability after Veritas separated from Symantec. Only branding has changed and the other things remain same if we talk about the products.
To know the difference between Proxy and Phantom resources, first know what are these resources and when they are used. Once this is clear, you yourself will be able to differentiate between them.
What Are Proxy and Phantom Resources?
Proxy resource is the resource which is used to copy the state of other resources. In simple terms, it just monitors and mirror the state of another resource.
Please note that it does not online or offline the resources, it just monitors them and mimic their current state.
It is very beneficial if your multiple resources depend upon single physical device such as a network interface card (NIC). So the proxy resource cannot online or offline the NIC resource, but it can monitor it and other resource can depend upon the actual state of the NIC resource through proxy.
Thus, through proxy resource multiple service groups can monitor the same network interfaces and thus also minimizing the VCS configuration. Configuring proxy resource is easy and we would talk about in our next tutorials.
Phantom resource can confuse the beginners. So they should know how VCS determines the state of service groups (SG) i.e. Online or Offline. VCS only shows the service group online if all the non-persistent resources are online.
So, if you only have persistent resources in your service group and they are online, VCS would not show the current state as online. It would show offline, because VCS cannot online or offline that service group. So we add an OnOff resource to determine the actual state of service group.
Difference Between Proxy and Phantom Resources
After reading above explanation of Proxy and Phantom resources, we are sure you must have got some idea what they do and why they are used. So you can differentiate between them.
In simple terms, a Phantom resource enables VCS to determine the status of service groups that do not include OnOff resources and are used in parallel service groups only.
Whereas Proxy resource help in mirroring the state of another resource by monitoring it, so multiple service group can be depended on a single service group containing that proxy resource.
We are sure now you know what is the difference between a proxy and phantom resource and why they are used. If you like the article share it with your friends and do not forget to subscribe to Storage Tutorials for more such tutorials on different topics. You can also bookmark this page for your future reference.