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Community Forum > Too Much Memory for ZFS?

Have you ran into a problem on ZFS where there can be too much memory in a system that it takes up all the CPU cycles when freeing up memory?
Is there any support cases with QuantaStor with similar issues below?


http://www.zfsbuild.com/2012/03/05/when-is-enough-memory-too-much-part-2/

Quote from the forum thread mentioned above:

Matt Breitbach says:
September 10, 2012 at 11:25 am
We never found a great end-all solution to this. We’ve been seeing fewer problems as memory pressure increased (since a 1 time read wouldn’t elevate it into the arc). You may want to actually try shrinking the amount of RAM available to your server. I know it’s a silly thing to try, but dropping your RAM back to 96GB may actually be a good thing. If you’re seeing that much data sitting in the arc that’s only been accessed once, you’ve got too much RAM. I know that all of the documentation says that you can never have too much RAM, but the reality is that right now, with that much memory being mostly idle, it’s hurting during svmotions more than it would hurt by decreasing the amount of RAM.

June 9, 2015 | Unregistered CommenterDon N.

Hello Don,

The referenced post is referred to a performance problem freeing memory on Nexenta which is based on Solaris/Illumos. I believe that is an operating system problem and don't feel it translates to the ZFS on Linux used in QuantaStor. We have not experienced any problems with large memory machines.

Thanks,
J.P. McGlinn
OSNEXUS Support

June 11, 2015 | Registered CommenterJ.P. McGlinn