disk devices speed is ugly

Andriy Gapon avg at FreeBSD.org
Wed Feb 15 09:50:31 UTC 2012

on 15/02/2012 06:50 Scott Long said the following:
> The ARC is limited by available wired memory; attempts to allocate such
> memory will evict pages from the buffer cache as necessary, until all
> available RAM is consumed.  If anything, ZFS starves the rest of the system,
> not the other way around, and that's simply because the ARC isn't integrated
> with the normal VM.

I just would like to add for completeness that this is an oversimplified view of
ARC's behavior.  ARC tries to monitor overall memory usage and tries to throttle
itself when necessary.  It also reacts to lowmem signal from pagedaemon.

Andriy Gapon

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