Re: Problems unmounting/fssyncking extern UFS filesystem

Date: Mon, 27 Nov 2006 14:53:06 +0100 (CET)
From: Oliver Fromme <olli@xxxxxxxxxxxxxxxxx>
Sender: owner-freebsd-stable@xxxxxxxxxxx

O. Hartmann wrote:
> Maybe amd() dismounts to early ... Don't know. Maybe the magic
> 'sync;sync;sync' before dismounting will help, I'll try it.

As far as I know, that's not different from calling "sync"
just once. It might make more sense to put a little sleep
between the sync calls, though.

The traditional mantra was
sync
sync
sync
and not sync;sync;sync. The reason was timing. By entering the sync
command three times as fast as anyone could type, the sync could
reliably complete.

That mantra is about 25 years old, so its validity on modern hardware is
questionable, but the need for a delay is very real. I would suggest
something like: sync && sleep 5
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