From owner-freebsd-fs@FreeBSD.ORG Mon Mar 10 14:36:42 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id CE8C4E37 for ; Mon, 10 Mar 2014 14:36:42 +0000 (UTC) Received: from mail-yh0-x22e.google.com (mail-yh0-x22e.google.com [IPv6:2607:f8b0:4002:c01::22e]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 91CC3FE3 for ; Mon, 10 Mar 2014 14:36:42 +0000 (UTC) Received: by mail-yh0-f46.google.com with SMTP id b6so4118519yha.33 for ; Mon, 10 Mar 2014 07:36:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=Pze036IIEO8Bm5KwGRxFEp7CR/95sacq8F671Hiis+Y=; b=gQ399k6Y3EUPGhFzJmBYtFpG2jzs2XCCBsLjTgLxfMIU+TQYj7qnbSwnyubzRgqbPk 97HgLXEG5KnuLjOdTryaymKvJYQPiI+EJTwWkJAgLW70YxjN9ZUT03eeE0Q/hQ6O39WH X2X13kWDQYSg6pgOJFU3p6Idt2oXEwKePclAZeEBLk3mOa6tZ+Ep+YwKY+DSRtpkWD0U GpNOyTygtmRj6L0hLPPo+bmHuvEfv/EhZxajD0OK7fpY+zEyFyDNCN49FNfHUCH4d8nt j7ZmwcKE3PPU2hfgj63mhCLDjN0leURJdlGPMFCF/jTu7ptm8JsXEtdycd3ImBRgWOMT DkOg== MIME-Version: 1.0 X-Received: by 10.236.157.167 with SMTP id o27mr2271381yhk.127.1394462201794; Mon, 10 Mar 2014 07:36:41 -0700 (PDT) Received: by 10.170.54.17 with HTTP; Mon, 10 Mar 2014 07:36:41 -0700 (PDT) In-Reply-To: <20140310140343.GA22517@pcjas.obspm.fr> References: <20140310140343.GA22517@pcjas.obspm.fr> Date: Mon, 10 Mar 2014 14:36:41 +0000 Message-ID: Subject: Re: ZFS & Dedup & SSD. From: krad To: Albert Shih Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: FreeBSD FS X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Mar 2014 14:36:42 -0000 you dont use the ssd for dedup, more you use it as an l2arc device. Hopefully the full dedup table is stored in the cache. Alternatively just but LOTS of ram in you machine. In my experience dedup is very expensive, and unless the ratio is very high its cheaper and simpler just to buy the extra storage. Often you can get the benefits of dedup, without actually using is though. eg clone a zfs fs rather than clone at the vm level for instance. Thing will diverge over time of course, but it can give you a lot of what u need. On 10 March 2014 14:03, Albert Shih wrote: > Hi all, > > If I use a ssd for dedup, what's happen if I loose the content of the ssd= . > > Can I get the data event without the ssd ? > > I ask that because SSD is expensive so make raid on SSD is more expensive= . > So I like to use just one SSD for the dedup. > > Regards. > > JAS > > > -- > Albert SHIH > DIO b=E2timent 15 > Observatoire de Paris > 5 Place Jules Janssen > 92195 Meudon Cedex > France > T=E9l=E9phone : +33 1 45 07 76 26/+33 6 86 69 95 71 > xmpp: jas@obspm.fr > Heure local/Local time: > lun 10 mar 2014 15:02:05 CET > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >