From owner-freebsd-current@FreeBSD.ORG Mon Apr 16 10:28:55 2007 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4F6D816A403 for ; Mon, 16 Apr 2007 10:28:55 +0000 (UTC) (envelope-from garyj@jennejohn.org) Received: from mail08c.verio.de (mail08c.verio.de [213.198.55.118]) by mx1.freebsd.org (Postfix) with SMTP id AA36013C4AD for ; Mon, 16 Apr 2007 10:28:54 +0000 (UTC) (envelope-from garyj@jennejohn.org) Received: from mx98.stngva01.us.mxservers.net (198.173.112.35) by mail08c.verio.de (RS ver 1.0.95vs) with SMTP id 2-0328779332 for ; Mon, 16 Apr 2007 06:28:53 -0400 (EDT) Received: from mmm808.verio.de [213.198.55.120] (EHLO mmm808.verio.de) by mx98.stngva01.us.mxservers.net (mxl_mta-1.3.8-10p4) with ESMTP id b4e43264.16345.067.mx98.stngva01.us.mxservers.net; Mon, 16 Apr 2007 06:22:03 -0400 (EDT) Received: (qmail 74315 invoked from network); 16 Apr 2007 10:28:51 -0000 Received: from unknown (HELO peedub.jennejohn.org) (89.54.131.180) by with SMTP; 16 Apr 2007 10:28:51 -0000 Received: from jennejohn.org (localhost [127.0.0.1]) by peedub.jennejohn.org (8.14.1/8.14.1) with ESMTP id l3GASo1W010585 for ; Mon, 16 Apr 2007 12:28:50 +0200 (CEST) (envelope-from garyj@jennejohn.org) Message-Id: <200704161028.l3GASo1W010585@peedub.jennejohn.org> X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.0.4 To: freebsd-current@freebsd.org From: Gary Jennejohn Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 16 Apr 2007 12:28:50 +0200 Sender: garyj@jennejohn.org X-Spam: [F=0.5146094655; heur=0.500(0); stat=0.504; spamtraq-heur=0.510(2007022501)] X-MAIL-FROM: X-SOURCE-IP: [213.198.55.120] X-SF-Loop: 1 Subject: Some comments on ZFS 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: Mon, 16 Apr 2007 10:28:55 -0000 I've now moved to using ZFS on my -current machine. Very nice not having to worry about the size of a FS. My box has 2GB of memory and an AMD64 X2 4200+. However, I've noticed some things which I find rather strange. I. My old setup looked like this: a) 2 36GB SCSI disks on AHC UFS/soft-updates - 80MB/s max. transfer rate. /usr/src was on one disk and /usr/obj on the other. b) 2 SATA1 drives hooked to AHC using SATA -> SCSI adapters GJOURNAL on top of UFS/soft-updates - also 80MB/s max. transfer. These were also mounted async. II. The new setup: a) 1 36GB SCSI drive hooked to AHC - UFS/soft-updates. /usr/src is on this disk. b) 2 500GB SATA1 drives ZFS-mirrored. One is hooked up to the MB and the other is hooked up to the AHC using a SATA -> SCSI adapter. c) 1 300GB and 1 160GB SATA drive ZFS-concatenated. One is hooked up to the MB and the other is hooked up to the AHC using a SATA -> SCSI adapter. /usr/obj is on this one. These are the same disks as in I(b). I've turned off atime and compression on all ZFS file systems. With the old setup I saw: a) ``make -j2 buildworld'' usually pegged the CPU at 97%. b) transferring data over NFS from a Linux client to this one pretty much always saturated the 100Mb/s link. With the new setup: a) ``make -j2 buildworld'' only reaches about 70% CPU load. Is ZFS stealing so much CPU? b) while transferring data from I(b) to II(b) I saw several hard hangs of the machine without any error messages or warnings (I was working on the console). The only recourse was a hard reset. It turned out that some directories were somehow pathological and the box always hung while trying to copy them (I made several attempts). The only solution was to delete these (fortunately unimportant) directories. c) transferring data over NFS from the same Linux client to this one (target II(c)) pretty much never saturates the 100Mb/s link. The CPU load wasn't all that high - maybe 3% or 4%. Is there any ZFS setting analogous to async which I could use to speed up transfers? -- Gary Jennejohn / garyjATjennejohnDOTorg gjATfreebsdDOTorg garyjATdenxDOTde