We are planning to have a Dashboard which shows how much storage is being used in the server (web or database server) and what % of storage capacity will be in future.
i.e. we want to predict how much storage space needed in future based on the current trend.
1) How to get Storage utilized and free from the server to the splunk?
2) Based on the above data - The Dashboard should show how much storage space would be required in future based and what is the usage currently.
1) There are multiple ways to get storage metrics out of your server and it depends on your environment set up.
One of the ways is to configure a scripted input in your servers using universal forwarder and get usage information forwarded to Splunk. Your script could be as simple as running df -h command which gives you the required information
2) Once you have the usage information available in splunk, then you can use Predict command to get basic predictions. Have a look at the doc for more information about algorithms and usage.
e.g index=resources earliest=-24h |timechat span=1h max(usage) as usage|predict usage