SFILES are logical containers within commvault that holds the unique signatures that is written during the deduplication process of a Backup. It would not be specifically tied to any server. The point of deduplication is to minimize space consumption at the physical disk layer, by using pointers and references when associating to Backup jovs. 1 SFILE could be tied to many jobs associated to multiple servers and IDA. As such SFILE or any data written at the disk layer on Commvault should not be manipulated or deleted.
Hopefully that answers your question on SFILE