Re: Very large swap

At 07:08 14/10/2011, Dennis Glatting wrote:

This is kind of stupid question but at a minimum I thought it would be interesting to know.

What is the limitations in terms of swap devices under RELENG_8 (or 9)?

A single swap dev appears to be limited to 32GB (there are truncation messages on boot). I am looking at a possible need of 2-20TB (probably more) with as much main memory that is affordable.

I used 40 GB swap in 8.2. I wanted to test if caching files/data on memory swap were faster than an ordinary, always the same, standard approach of read/write from/to disk when need. It was faster, not a lot faster but mesurable. Of course when app exits files/data is lost.

I am working with large data sets and there are various ways of solving the problem sets but simply letting the processors swap as they work through a given problem is a possible technique.

Processors, memory, storage, and other hardware are open issues but for the minute I'm doing things on the cheap, which, admittedly, has a certain intellectual amusement factor.


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