I performed the following steps to get the sprel file and process back in order:
- Stop the FAST search service (see Properly Stop and Start FAST Search for SharePoint 2010).
- Delete the sprel file at C:\FASTSearch\var\log\sprel.
- Started the FAST search service
- Run the following in FAST Search Management Shell:
- Check the log files in: C:\FASTSearch\var\log\sprel and verify the new file created.
nctrl stop sprel nctrl start sprel