Xsan 3: Invisible "__defragtmp" files are created after using snfsdefrag
When defragmenting a file with snfsdefrag on systems running OS X Mountain Lion v10.8.4 and earlier, 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.
Update all Xsan systems to OS X Mountain Lion v10.8.5 or later before running snfsdefrag.
For systems running older versions of OS X, workaround the issue by changing directories to a path that is not on an Xsan volume (such as the root directory) before running snfsdefrag, and avoid using snfsdefrag's recursive option (-r).
If you need to recursively defragment files in a directory on an Xsan volume, you can do so by running snfsdefrag from the find utility. For example:
cd /
sudo find /Volumes/MyVolume/some_directory -type f -exec snfsdefrag '{}' \;
Alternatively, you can use snfsdefrag normally as the file's owner.
Learn more
Despite the alert messages, snfsdefrag does successfully defragment the file.
snfsdefrag will show output similar to this:
$ sudo snfsdefrag -m0 -r -v /Volumes/MyVolume/defrag_test
/Volumes/MyVolume/defrag_test/héllo.txt: 1 extent: can't bulk create temp file "/Volumes/MyVolume/defrag_test/héllo.txt__defragtmp", File exists
new extent count 1, done.
Can't stat '/Volumes/MyVolume/defrag_test/héllo.txt__defragtmp' - No such file or directory
After defragmenting a file, when using ls to list files in the directory, you may see results similar to this:
ls: héllo.txt__defragtmp: No such file or directory
The invisible "__defragtmp" files left behind do not contain any data and can be safely ignored. The same "No such file or directory" message will appear if you attempt to delete the "__defragtmp" file with the rm command.
