From can I see, Splunk continues to run but I would like to know what happens to the cold data which meets the criteria to be frozen? Once the frozen directory is made accessible, does Splunk continue to freeze the data, or was it already removed from the index?
The script to move data to the frozen directory is run.
There is no space to copy the data, or access is not available. This is logged in splunkd.log under the BucketMover category. The message will look something like the following.
ERROR BucketMover - aborting move because recursive copy from src='/opt/splunk/var/lib/splunk/internaldb/db/db143590169114356965401132' to dst='/tmp/test/inflight-db14359016911435696540_1132' failed (reason='Permission denied')
The cold bucket is not removed.
Once the issue preventing the script from freezing your data is resolved, the normal freezing process will resume.
If no action is taken to resolve the issue, the disk will eventually fill up and all indexing will stop.