On Sun, 23 Nov 2008, Bob Netherton wrote: >> This argument can be proven by basic statistics without need to resort >> to actual testing. > > Mathematical proof <> reality of how things end up getting used.
Right. That is a good thing since otherwise the technologies that Sun has recently deployed for "Amber Road" would be deemed virtually useless (as would most computing architectures). It is quite trivial to demonstrate scenarios where read caches will fail, or NV write cache devices will become swamped (regardless of capacity) and worthless. Luckily, these are not the common scenarios for most users. For the write cache case it may be seen that if the volume of writes continually exceeds the write rate of the backing store and is continually to new locations, then the write cache becomes useless since it will always become full. The read cache case is subject to the normal rules which require that the read cache needs to be large enough to contain the common "working set" of data in order for it to be effective. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
