When defragmenting a file with snfsdefrag, an invisible "__defragtmp" file may be created which cannot be deleted.
This issue may occur when the following are true:
The defragmented file’s name contains precomposed Unicode characters, such as letters with diacritical marks (an accent, grave, or umlaut).
snfsdefrag is run by root.
snfsdefrag is run when the current working directory is on an Xsan volume, or snfsdefrag’s recursive option (-r) is used.