Due to special requirements to delete files on the filer via NFS mounts and ensure they are not recoverable even at the block level, we are evaluating Linux tools such as srm and shred. My questions are:
1. Is there a better way to delete specific files to meet the requirements and ensure they are unrecoverable?
2. After deleting the files, they can still be recovered via snapshots. Is there a difference between
a. remove all snapshots first and then delete the files vs.
b. delete files first and then remove all snapshots?
I am concerned about if deleting files first, since snapshots are still holding the data blocks, the data blocks may still be intact even after snapshots are removed (assuming removing snapshots is just freeing up the pointers, not touching the data blocks).