Date: Tue, 17 Jun 2008 17:40:09 +0200 (CEST) From: Oliver Fromme <olli@lurza.secnetix.de> To: freebsd-questions@FreeBSD.ORG, roberthuff@rcn.com, chris@vindaloo.com Subject: Re: Replacing tape changer with USB disk drives. Message-ID: <200806171540.m5HFe92o057907@lurza.secnetix.de> In-Reply-To: <20080617162205.S8299@wojtek.tensor.gdynia.pl>
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Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl> wrote: > > > > > > you must have something wrong. my USB drive gets 27MB/s. yes this > > > 480Mbit/s is USB isn't real, but half of it is. > > > > I agree. > > Want to take this private and help figure out what's wrong? > > :-) > > i simply have no idea why it could work so slow. Cheap controller in the USB enclosure. I've used quite a few USB enclosures in the past years, and there are significant performance differences. As a rule of thumb, the cheaper the box, the slower it is. Of course there are exceptions to that rule. By the way, for backup purposes I use a hot-swappable IDE drive frame. The one I use is PATA (UDMA-133), but there are also ones for SATA. It's much faster than USB and more reliable. You can use atacontrol(8) to attach and detach the drive while the system is running. (For that to work reliably, the frame must be the only device on its channel, i.e. no slave, in the PATA case.) Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "It combines all the worst aspects of C and Lisp: a billion different sublanguages in one monolithic executable. It combines the power of C with the readability of PostScript." -- Jamie Zawinski, when asked: "What's wrong with perl?"
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