From owner-freebsd-performance@FreeBSD.ORG Mon May 30 16:01:03 2005 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8C04316A41F for ; Mon, 30 May 2005 16:01:03 +0000 (GMT) (envelope-from tuliogs@pgt.mpt.gov.br) Received: from mitra.mpt.gov.br (mail.pgt.mpt.gov.br [200.157.62.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id E9AE243D1D for ; Mon, 30 May 2005 16:01:01 +0000 (GMT) (envelope-from tuliogs@pgt.mpt.gov.br) Received: from [10.0.0.136] (516e.pgt.mpt.gov.br [10.0.0.136]) by mail.pgt.mpt.gov.br (8.13.1/8.13.1) with ESMTP id j4UG0wnc096423 for ; Mon, 30 May 2005 13:00:58 -0300 (BRST) (envelope-from tuliogs@pgt.mpt.gov.br) Message-ID: <429B38C7.5040405@pgt.mpt.gov.br> Date: Mon, 30 May 2005 13:01:11 -0300 From: =?ISO-8859-1?Q?Tulio_Guimar=E3es_da_Silva?= User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-performance@freebsd.org References: <428CF20F.50607@pgt.mpt.gov.br> <428D0D79.7010506@rcn.com> <428DFF35.1000409@pgt.mpt.gov.br> In-Reply-To: <428DFF35.1000409@pgt.mpt.gov.br> Content-Type: multipart/mixed; boundary="------------090500060903070709060002" X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: rmt as a bottleneck - Was: Weird behaviour of AIT-3 and (g)tar X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 May 2005 16:01:03 -0000 --------------090500060903070709060002 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by mail.pgt.mpt.gov.br id j4UG0wnc096423 Updates to an old problem. I=B4m splitting the original thread in 2,=20 since there are 2 different questions, one of which I guess is for=20 -hardware and the other, for -performance, then I=B4m x-posting this one. Here are other things I=B4ve been experimenting with... first, I=B4ll=20 present the machines: - Omega: HP ML 110, 512MB RAM, 4x80GB 7200rpm SATA in RAID5 via=20 HighPoint RR8120A, AIT-3 tape via Adaptec Ultra160; - Theta: HP DL 380, 1GB RAM, 6x72.8GB@10krpm SCSI in RAID5 via HP=20 Smart Array 6i Here=B4s what I got: theta# /usr/bin/time -h gtar --atime-preserve --same-owner -cvpf=20 omega:/home/teste /home/bkp/home/ gtar: Removing leading `/' from member names home/bkp/home/ home/bkp/home/bkp/ home/bkp/home/bkp/rsh-vulcano.sh home/bkp/home/bkp/2005-01/ home/bkp/home/bkp/2005-01/vulcano_2005-01-31.tar.gz ^Ctime: command terminated abnormally 8m24.24s real 0.15s user 0.78s sys ... and then... omega# ls -laFG /home/teste -rw-r--r-- 1 root wheel 189020160 May 30 12:02 /home/teste omega# this gives me exact 375.040 Bytes/second. then I changed my approach: omega# /usr/bin/time -h rsh theta gtar --atime-preserve --same-owner -C=20 /home/bkp -cvpf - home/ >/home/teste1 home/ home/bkp/ home/bkp/rsh-vulcano.sh home/bkp/2005-01/ home/bkp/2005-01/vulcano_2005-01-31.tar.gz home/bkp/2005-01/liam_2005-01-24.tar.gz home/bkp/2005-01/cache_www2005-01-29.tar.gz ^C 9m33.75s real 8.57s user 3m6.08s sys omega# ls -laFG /home/teste1 -rw-r--r-- 1 root wheel 6396353720 May 30 12:35 /home/teste1 omega# Observe that I bypassed rmt; that bumped the transfer rate to=20 10.976.153,96 Bytes/s, almost 30x faster. Should this really happen?=20 (And yes, I read rmt(8), but found nothing about this. :( ). Thanks for your help; Tulio Tulio Guimar=E3es da Silva wrote: > Hi Gary, > ouch! That=B4s quite disappointing... :( We had already noticed this=20 > kind of behaviour with DDS-* tapes, but we got some progress varying=20 > the block size... and yup, I=B4m really using gzipped data. :S > For AIT-3, however, i thought this hardware compression was something=20 > about using lower tape=B4s phisical-rolling speeds or alikes, but I=20 > could never really find anything concrete about the methods... the=20 > only one thing I found was they could use "variable block sizes", but=20 > that=B4s all. Again, not many details. Anyway, I=B4m giving up the idea= of=20 > compression for now. > If something, I=B4m noticeing that (at least with -b 10) it becomes (a= =20 > lot) slower with time, but I guess this would be more of a question to=20 > the -performance list. > Add: while writing this message, I remembered to check the 700V=B4s=20 > "Product Specification Manual", and they mention something about=20 > dual-partitions, but it seems something that needs to be implemented=20 > at driver level, since it includes SCSI commands. In this case, I=20 > would need to format the tape as a 2-partition one... any clue about=20 > if and/or how that works on FreeBSD? > Thanks again, > > Tulio > > Gary Corcoran wrote: > >> Tulio Guimar=E3es da Silva wrote: >> >>> Hello again, >>> >>> I=B4m having some trouble putting a Sony SDX-700V SCSI AIT-3 unit=20 >>> to work on FreeBSD 5.3-RELEASE. >> >> >> ... >> >>> Besides the speed, hardware compression seems to not being=20 >>> funcional either. I already tried every 4 possible dip switch=20 >>> setting for compression, but I am still not able to transfer a 180GB=20 >>> archive to a (should-be) 260GB medium. >> >> >> >> I can't help you with most of your problems, but regarding the=20 >> "compression"... >> >> I would guess that if you have 180GB to backup, it's not all text. :) >> When I last used a tape drive years ago, when writing to a 2GB tape >> that would supposedly hold 4GB compressed, I could fit only about 1.9G= B >> before the tape was full. Turning off hardware compression, I could f= it >> 2GB. The problem was that I was saving already compressed multimedia=20 >> files, >> and the tape drive's "compression" just added overhead and took up=20 >> more space. >> So unless you're backing up text or similar files, don't believe the >> marketing hype about getting 2x the amount onto your tapes... >> >> Gary > > >------------------------------------------------------------------------ > >_______________________________________________ >freebsd-hardware@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-hardware >To unsubscribe, send any mail to "freebsd-hardware-unsubscribe@freebsd.o= rg" > =20 > --------------090500060903070709060002--