"The main difference between ext2 and FFS is that ext2 makes no
guarantee about consistency of the file system or whether an operation
is permanently on the disk when the file system call completes.
[...] This consistency model is not without drawbacks and may not be
appropriate at all for some applications. Because ext2 makes no
guarantee about the order of operations and when they are flushed to
disk, it is conceivable (although unlikely) that later modifications
to the file system would be recorded on disk but earlier operations
would not be. Although the file system consistency check would
ensure that the file system is consistent, the lack of ordering on
operations can lead to confused applications or, even worse, crashing
applications because of the inconsistencies in the order of
modifications to the file system."
_Practical File System Design_, Dominic Giampaolo, p. 36
Unfortunately, the author goes into no deeper detail about the
danger, and so the above text remains just vague enough to give me a
gnawing case of FUD. Would some knowledgeable person on this list
care to enlighten me? I'm particularly concerned about how an
application could potentially become confused and/or crash because of
this.
Even if the danger has only one chance in a thousand million of
occurring, I'd still like to understand why the probability is that
small, and why it is nonzero, and what, if anything, an application
programmer seeking robustness could do to work around it.
--
Mirian Crzig Lennox Systems Anarchist
"There's a New World Order coming every minute.
Make mine extra cheese."
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