Date: Mon, 25 Jun 2012 21:55:07 +0200 From: Joerg Wunsch <j@uriah.heep.sax.de> To: Holm Tiffe <holm@freibergnet.de>, "Kenneth D. Merry" <ken@freebsd.org>, freebsd-scsi@freebsd.org Subject: Re: Kernel panic in FreeBSD-8.3 from UFS Message-ID: <20120625195507.GO2291@uriah.heep.sax.de> In-Reply-To: <20120625193138.GB82032@beast.freibergnet.de> References: <B2FD678A64EAAD45B089B123FDFC3ED72B9F6C1F79@inbmail01.lsi.com> <20120601124338.GU2358@deviant.kiev.zoral.com.ua> <B2FD678A64EAAD45B089B123FDFC3ED72B9F6C1F7F@inbmail01.lsi.com> <20120601125824.GV2358@deviant.kiev.zoral.com.ua> <B2FD678A64EAAD45B089B123FDFC3ED72B9F6C21A7@inbmail01.lsi.com> <20120606170640.GA98428@nargothrond.kdm.org> <20120625135543.GA58915@beast.freibergnet.de> <20120625155316.GA37535@nargothrond.kdm.org> <20120625193138.GB82032@beast.freibergnet.de>
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As Holm Tiffe wrote: > ..., but the performance is somewhere below > the basement: > > 0: 0x1a:DLTapeIV(20GB) variable 81633 IDRC > 1: 0x1a:DLTapeIV(20GB) variable 81633 IDRC > 2: 0x1a:DLTapeIV(20GB) variable 81633 IDRC > 3: 0x1a:DLTapeIV(20GB) variable 81633 IDRC > --------------------------------- > Current Driver State: at rest. > --------------------------------- > File Number: 0 Record Number: 0 Residual Count 0 > # dd if=/dev/zero of=/dev/sa1 bs=64k count=10000 > 10000+0 records in > 10000+0 records out > 655360000 bytes transferred in 125.909593 secs (5205005 bytes/sec) I don't think 5 MB/s is a poor value for a DLT-2000. On a DLT-8000 (with wide SCSI), I get a little more than 10 MB/s provided the data source is fast enough. > It think the DLT drive should be streaming while writing 64K Blocks from > /dev/zero, shouldn't it? No, it moves back and forward all the time. Turn off hardware compression, the drive cannot compress your zeros as fast as you want. > This thing is reading even slower than writing, the Drive makes pauses of > almost 10 seconds between the really short runs. That's indeed poor. -- cheers, J"org .-.-. --... ...-- -.. . DL8DTL http://www.sax.de/~joerg/ NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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