dangerous situation with shutdown process

Matthias Buelow mkb at incubus.de
Mon Jul 18 15:14:11 GMT 2005

Paul Mather <paul at gromit.dlib.vt.edu> writes:

>Why would that necessarily be more successful?  If the outstanding
>buffers count is not reducing between time intervals, it is most likely
>because there is some underlying hardware problem (e.g., a bad block).
>If the count still persists in staying put, it likely means whatever the
>hardware is doing to try and fix things (e.g., write reallocation) isn't
>working, and so the kernel may as well give up.

So the kernel is relying on guesswork whether the buffers are flushed
or not...

>You can enumerate the buffers and *try* to write them, but that doesn't
>guarantee they will be written successfully any more than observing the
>relative number left outstanding.

That's rather nonsensical. If I write each buffer synchronously (and
wait for the disk's response) this is for sure a lot more reliable than
observing changes in the number of remaining buffers. I mean, where's
the sense in the latter? It would be analogous to, in userspace, having
to monitor write(2) continuously over a given time interval and check
whether the number it returns eventually reaches zero. That's complete
madness, imho.


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