ZFS and UFS on the same box. Cache memory allocation issue.

Emil Mikulic emikulic at gmail.com
Fri Dec 18 10:15:26 UTC 2009

On Fri, Dec 18, 2009 at 11:49:47AM +0300, Alexander Zagrebin wrote:
> As result UFS returns memory to "free" pool and ZFS can allocate it for ARC.
> It significantly increases ZFS performance.
> Is there an another workaround?

I use: (cd /somefs && sudo umount /somefs)

The umount fails, but it does clear the buffer cache!  Memory reported
as "inactive" by top decreases.  I find this to be a really handy trick
when benchmarking I/O.  ;)

Unfortunately, it doesn't work on the root filesystem.


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