From owner-freebsd-hackers@FreeBSD.ORG Mon Dec 17 14:07:09 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 5939A3DC for ; Mon, 17 Dec 2012 14:07:09 +0000 (UTC) (envelope-from freebsd-hackers@m.gmane.org) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) by mx1.freebsd.org (Postfix) with ESMTP id 0251B8FC17 for ; Mon, 17 Dec 2012 14:07:08 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1TkbLh-0008RL-Vt for freebsd-hackers@freebsd.org; Mon, 17 Dec 2012 15:07:17 +0100 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Dec 2012 15:07:17 +0100 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Dec 2012 15:07:17 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-hackers@freebsd.org From: Ivan Voras Subject: Re: iSCSI vs. SMB with ZFS. Date: Mon, 17 Dec 2012 15:06:55 +0100 Lines: 57 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig62AD3874C4FF67C726A81368" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:14.0) Gecko/20120812 Thunderbird/14.0 In-Reply-To: X-Enigmail-Version: 1.4.3 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Dec 2012 14:07:09 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig62AD3874C4FF67C726A81368 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 12/12/2012 17:57, Zaphod Beeblebrox wrote: > The performance of the iSCSI disk is > about the same as the local disk for some operations --- faster for > some, slower for others. The workstation has 12G of memory and it's > my perception that iSCSI is heavily cached and that this enhances it's > performance. The second launch of a game ... or the second switch > into an area (ie: loading a specific piece of geometry again) is very > fast. > The performance on the SMB share is abysmal compared to the > performance on the iSCSI share. At the very least, there seems to be > little benifit to launching the same application twice --- which is > most likely windows fault. Think about what you have there: With iSCSI you have a block device, which is seen on your workstation as a disk drive, on which it creates a "local" file system (NTFS), and does *everything* like it is using a local disk drive. This includes caching, access permission calculations, file locking, etc. With a network file system (either SMB or NFS, it doesn't matter), you need to ask the server for *each* of the following situations: * to ask the server if a file has been changed so the client can use cached data (if the protocol supports it) * to ask the server if a file (or a portion of a file) has been locked by another client This basically means that for almost every single IO, you need to ask the server for something, which involves network traffic and round-trip delays. (there are smarter network protocols, and even extensions to SMB and NFS, but they are not widely used) --------------enig62AD3874C4FF67C726A81368 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAlDPJwAACgkQ/QjVBj3/HSwYPwCfQDo/0dNhAEO80b1FxsXf6ymb D80Ani4IzL/emewWeNCFV0u4etX2G8G0 =K/Pd -----END PGP SIGNATURE----- --------------enig62AD3874C4FF67C726A81368--