From owner-freebsd-questions@FreeBSD.ORG Wed Jan 5 23:38:52 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 1AF3D1065696 for ; Wed, 5 Jan 2011 23:38:52 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 9C7628FC13 for ; Wed, 5 Jan 2011 23:38:51 +0000 (UTC) Received: by fxm16 with SMTP id 16so15449360fxm.13 for ; Wed, 05 Jan 2011 15:38:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=dNaygllxxq4GAGChtCa0LQbOP0ZAQWGAuavg9j9YSUw=; b=lCYZ+rHp92H3AnqF+C1IlQNHD8umvRiYkag4dfz1jMzv6K1AiPnTK5SI+DN12vgMY1 qqvnjTFqwPAzX6LH5xEToikBTz12r1V5fTOeLggFEBrhuh7bJXknI7IFoGNaAUSdNFIa AVYn+onQ0FlwiUt5VhcR3MnObY8ZPf0TkkzbU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=KCp8DP4vxbEnYZ366X3iMamdVgZg9umW2sTW3Djedw1KSz7ibL5ylOWANgNA5o3eDK HP4nRQ0TgwLTnl4HwQhOMS8eHRInaDHJyxNljr55YCR5z1PuUqYf3gh5Aony1L9Qo8cS vvfgItF5n4B1iwA8K0+zEZwkFqBFZCcaXU6oA= MIME-Version: 1.0 Received: by 10.223.116.1 with SMTP id k1mr2094406faq.51.1294270730439; Wed, 05 Jan 2011 15:38:50 -0800 (PST) Received: by 10.223.114.4 with HTTP; Wed, 5 Jan 2011 15:38:50 -0800 (PST) In-Reply-To: <27348_1294270392_4D24FFB8_27348_5874_1_D9B37353831173459FDAA836D3B43499A7AF90D6@WADPMBXV0.waddell.com> References: <009b01cbad28$883d31c0$98b79540$@com> <19331_1294269649_4D24FCD1_19331_11348_1_D9B37353831173459FDAA836D3B43499A7AF90D4@WADPMBXV0.waddell.com> <20110105232403.000056a2@unknown> <27348_1294270392_4D24FFB8_27348_5874_1_D9B37353831173459FDAA836D3B43499A7AF90D6@WADPMBXV0.waddell.com> Date: Wed, 5 Jan 2011 17:38:50 -0600 Message-ID: From: Adam Vande More To: Gary Gatten Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Bruce Cran , Jeff Whitman , "freebsd-questions@freebsd.org" Subject: Re: Swap Space 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: Wed, 05 Jan 2011 23:38:52 -0000 On Wed, Jan 5, 2011 at 5:33 PM, Gary Gatten wrote: > > > Correct me if I'm wrong, but if necessary one could add (and > > activate) a secondary / additional swap file if necessary without > > rebooting. So maybe start with a few gig and add an additional swap > > file if necessary? > > Swapping to a file is really slow and should only be done if absolutely > necessary since every read/write has to go through the filesystem code > which it doesn't do if done via a swap slice. > > Good point. It's been several years and back on v5 or 6 when I did > something like this. If there's unpartitioned space on the drive, can one > add a secondary swap partition real-time? I forget what I did here - I'm > sure I followed what's in the handbook re swap space. Probably did a swap > file... > Yes you can do that with swapon(1) It's been said though that FreeBSD memory paging algorithms take into account the system's entire available VM for deciding on when to act in low memory conditions and these parameters are tuned expect some of that to be swap space. That is why one reason there *should* be a least some swap space even on a system w/ plenty of RAM. -- Adam Vande More