From owner-freebsd-questions@FreeBSD.ORG Sat Oct 15 14:42:31 2011 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 42A2B106566B for ; Sat, 15 Oct 2011 14:42:31 +0000 (UTC) (envelope-from nec556@retena.com) Received: from resmaa13.ono.com (smtp13.ono.com [62.42.230.16]) by mx1.freebsd.org (Postfix) with ESMTP id CCAC18FC15 for ; Sat, 15 Oct 2011 14:42:30 +0000 (UTC) Received: from GogPortatil.retena.com (95.20.141.164) by resmaa13.ono.com (8.5.113) (authenticated as nec556@retena.com) id 4E5EF2B000C155EA; Sat, 15 Oct 2011 16:42:26 +0200 Message-ID: <4E5EF2B000C155EA@> (added by postmaster@resmaa13.ono.com) X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Sat, 15 Oct 2011 16:41:43 +0200 To: Dennis Glatting ,freebsd-questions@freebsd.org From: Eduardo Morras In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Antivirus: AVG for E-mail 10.0.1411 [1522/3953] Cc: Subject: Re: Very large swap X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Oct 2011 14:42:31 -0000 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. > >TIA