Bsd Now

This week, Allan is out of town, but since when has that ever stopped us from bringing you a new episode of BSDNow? We have news, This episode was brought to you by Headlines Unix's file durability problem (https://utcc.utoronto.ca/~cks/space/blog/unix/FileSyncProblem) Another article by Chris Siebenmann from the University of Toronto This time, the issue was a lost comment on his Python based blog which uses files on disk rather than a database After an unexpected restart of the system, a recently posted comment no longer existed The post goes on to investigate what the ‘right way’ to ensure file durability is The answer, as you might expect, is “it depends…” Normally, fsync() should work, but it seems with ext4 and some other file systems, you must also fsync() the directory where the file was created, or it might not be possible to find the file after a crash Do you need to fsync() the parent of that directory too? Then what is fdatasync() for? What about just calling sync()? “One issue is that unlike man