From owner-freebsd-questions@FreeBSD.ORG Thu Oct 7 20:20:46 2010 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 9B2B11065673 for ; Thu, 7 Oct 2010 20:20:46 +0000 (UTC) (envelope-from amsibamsi@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id E2B328FC1A for ; Thu, 7 Oct 2010 20:20:45 +0000 (UTC) Received: by wyb29 with SMTP id 29so618115wyb.13 for ; Thu, 07 Oct 2010 13:20:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=uG4ALlrp9Sfm6zaT9wTSamVEjS5Yv410thxNWZ+pW74=; b=jfz02SQ7lv3WewgiYl3aHSdcYha76RXLJ7NdU7mlWqUIT2hsiIbOMWLP565LFSoOjj DFMdNASwqM+VkH7DATyPfaZbGq8sNqVDwDI7f3vwbWC/sfsFKeRZmiqUV3H/k0nI7BUB szQ+y0xHjzow6thvmM1Jtmejjkp/7c+6xhcI8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=KnBKvNaAbufrribB38VfjBYuwYlscJEza229ZlaZhYaPpVK7skw9dxP7qe1k9gyyVm L/tDWaeiai0Z4w281sz9cp/T/Hr5UbnAfaWcXc/zPY+UKsFG/k5iQv98lhjcbKllPby1 /oj8VHIIKAq6FLsLr6yEAzU7uB8GAP+h+NKhI= Received: by 10.227.127.130 with SMTP id g2mr1401984wbs.67.1286482844653; Thu, 07 Oct 2010 13:20:44 -0700 (PDT) Received: from hulk.l.ttyv0.net (80-219-18-72.dclient.hispeed.ch [80.219.18.72]) by mx.google.com with ESMTPS id f14sm715347wbe.2.2010.10.07.13.20.42 (version=SSLv3 cipher=RC4-MD5); Thu, 07 Oct 2010 13:20:43 -0700 (PDT) Message-ID: <4CAE2B99.7020804@gmail.com> Date: Thu, 07 Oct 2010 22:20:41 +0200 From: Anselm Strauss User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.12) Gecko/20101006 Thunderbird/3.0.8 MIME-Version: 1.0 To: Adam Vande More , freebsd-questions@freebsd.org References: <4CA6FBC2.8080908@gmail.com> In-Reply-To: X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Subject: Re: Swap on ZFS 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: Thu, 07 Oct 2010 20:20:46 -0000 On 10/02/10 17:52, Adam Vande More wrote: > On Sat, Oct 2, 2010 at 4:30 AM, Anselm Strauss wrote: > >> Hi >> >> I have a virtual server with only 512 MB of memory but still want to run >> ZFS on it. >> >> Has there been any fix or workaround for this? I guess it does not help >> when I use a swap file on ZFS instead of a separate zvol. >> > > Make sure you are following this: > http://wiki.freebsd.org/RootOnZFS/GPTZFSBoot Please note swap is not a > ZVOL, it is a sepate partition. You'd have the same problem with ZVOL. > Also use i386, that will save you a bit of memory. Follow the ZFS tuning > guide. Even if you follow all those things, I'm not sure you'll be able to > get it stable. 512MB is really tight. > I now have the swap on a separate disk and it seems more stable. Although the server still has only 512 MB of RAM, runs on amd64 and I did no tuning. It's not a file server but compiling ports and running some services seems okay. I have seen multiple posts on the net where people put swap on ZFS. What sense does it make when every time the machine runs out of physical memory it freezes before it can allocate some swap memory. Does it only make sense in case you have additional non-ZFS swap?