Tuning SYSVR3 (Esix Rev D) (LONG!)

[Conor P. Cahill]

In article <N7970K8 at xds30.ferranti.com> karl at ficc.ferranti.com (Karl Lehenbauer) writes:
>Anyone have any idea how to reduce these sluggish periods without reducing
>the cache size and without reducing the reliability of the file system
>with respect to power outages or the performance?

You can't.  The problem is that the "dirty" blocks sit in the queue for a
specified amount of time (unless the block is needed for other uses) before
they are forced out by the kernel.  The amount of time is controlled by 
a kernel configuration parameter (NAUTOUP, I think).

The problem is that if you increase this variable, you decrease reliability.

Even if you set this variable to some high value, it is still possible 
that at that new time period following a large disk update, the system 
will slow down momentarily due to many dirty pages that still need to 
be written out, so you may be in a no-win situation.

-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
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