From owner-freebsd-current@FreeBSD.ORG Fri Dec 14 19:35:04 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 30D9516A420 for ; Fri, 14 Dec 2007 19:35:04 +0000 (UTC) (envelope-from freebsd-current@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id 9D8AA13C457 for ; Fri, 14 Dec 2007 19:35:03 +0000 (UTC) (envelope-from freebsd-current@m.gmane.org) Received: from list by ciao.gmane.org with local (Exim 4.43) id 1J3GHJ-0004Rf-Tp for freebsd-current@freebsd.org; Fri, 14 Dec 2007 19:32:57 +0000 Received: from 78-0-85-236.adsl.net.t-com.hr ([78.0.85.236]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 14 Dec 2007 19:32:57 +0000 Received: from ivoras by 78-0-85-236.adsl.net.t-com.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 14 Dec 2007 19:32:57 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-current@freebsd.org From: Ivan Voras Date: Fri, 14 Dec 2007 20:29:56 +0100 Lines: 53 Message-ID: References: <47606C09.2070209@isc.org> <47609F0A.7010805@clearchain.com> <47609FE3.8040606@barafranca.com> <4760B444.1080604@clearchain.com> <06CAC7FC-DB58-441D-A6E0-76D1D8133393@tamu.edu> <86ir31xwlu.fsf@ds4.des.no> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig1A1DEE1A2CE5DCBF3237FE53" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 78-0-85-236.adsl.net.t-com.hr User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) In-Reply-To: X-Enigmail-Version: 0.95.5 Sender: news Subject: Re: ZFS melting under postgres... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 14 Dec 2007 19:35:04 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig1A1DEE1A2CE5DCBF3237FE53 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable David Duchscher wrote: > On Dec 14, 2007, at 6:57 AM, Dag-Erling Sm=C3=B8rgrav wrote: >=20 >> David Duchscher writes: >>> So does anybody know of a battery backed NVRAM card that can be used >>> with FreeBSD that the ZIL could be offloaded to? >> >> Any CF card or similar will do. You don't need battery backup for >> flash memory. >=20 > I did think of that but is a CF card faster than a good SAS or SATA > drive?=20 Not in transfer rate, but it could help hugely with seek-intensive IO loads (since seeks are instantaneous on flash or other solid-state drives). In theory, they could be of immense benefit for databases and seek-intensive operations on file systems, but the limited bulk transfer rates and relatively small sizes (for decent money) currently prevent their wide-spread use. It would be logical to use a limited size SSD for something like a file system journal for a large file system, except that these kind of journals are usually not seek-intensive :) > Fastest ones I found have a top rating of 45MB/s. The one > battery backed NVARM card that showed up in a google search had a peak > rate of 533MB/s. The question seems moot though since FreeBSD doesn't > currently support them. If a NVRAM or SSD, or other technology presents the drive as a (S)ATA drive, there's no reason it shouldn't. --------------enig1A1DEE1A2CE5DCBF3237FE53 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFHYtm5ldnAQVacBcgRAuFqAKCMNnIyN55dgZ8C8SYfXPuTHAEUGACgyh4l 9zh8woR+VEufqAF8aCLjQik= =S9hA -----END PGP SIGNATURE----- --------------enig1A1DEE1A2CE5DCBF3237FE53--