> > All file systems provide writes by default which are > > atomic with respect to readers of the file. > > Surely, only in the absence of a crash - otherwise, > POSIX would require implementation of transactional > write semantics in all file systems. Or is that what > you meant by the last sentence in your post?
Well, that's part of what I meant, but the actual POSIX requirement is that a read which occurs while a write is in progress cannot see a partially-completed write. A system crash would tend to stop any writes in progress, so this particular requirement doesn't seem to apply. :-) > Update-in-place file systems can certainly support > large-than-disk-sector write atomicity - they just > have to use something like a transaction to do it. True ... I don't know of any which do, but they could. Maybe I should have said "update-in-place file systems which do not also write data to a separate log" to be more accurate.... Anton This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
