I'm currently facing an immediate situation where my Splunk Indexers are running of of the disk space. Please let me know what options are available.
There are several options for you. Please see below link for more detail.
https://splunk.box.com/v/dataoffload
The quick win is the TSIDX reduction.
https://docs.splunk.com/Documentation/Splunk/latest/Indexer/Reducetsidxdiskusage
Hadoop data roll would be the next when you have any Hadoop storage space.
https://docs.splunk.com/Documentation/Splunk/latest/Indexer/ArchivingindexestoHadoop
I hope this helps.