Date: Mon, 15 Jan 2001 10:04:33 -0700 (MST) From: Eric Lee Green <eric@estinc.com> To: Matthew Jacob <mjacob@feral.com> Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: Why filemarks in sardpos? Message-ID: <Pine.LNX.4.21.0101150942200.882-100000@h23.estsatnet> In-Reply-To: <Pine.BSF.4.21.0101132006280.14728-100000@beppo.feral.com>
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On Sat, 13 Jan 2001, Matthew Jacob wrote: > LOGICAL block position is different- I would expect block #Z to be 26 more > than block #A above- this shouldn't change. Again, assuming Z..A make it to > tape (if they don't that's a catastrophic error). > > I notice you're using MTIOCRSPOS- I think I would tend agree that this > wouldn't require a flush. Hardware position should probably stay where it is > now. And in fact at least one of the drives we must be compatible with (the Tandberg SLR line) will happily burp all over the floor if you attempt to use physical positioning. I assume that anybody else doing enterprise backup would have the same problem, so the logical positioning case is probably more common. > p.s.: Not all drives, btw, have a horrible speed loss with the flush > operation. DAT drives seem fine. DLTs are horribly affected. I noticed the horrible speed loss with a Seagate DDS-3 DAT drive. We're talking about going down to a max of 20K per second thruput when talking about small files (those < 20K in size). Taking out the flush got us back up to the full 1M/sec thruput of the DDS-3 DAT drive. > [ yes, I'll ignore your barbarous manners. the content *is* important- not > because BRU or ESTinc (ESTINK? New Unix errno?) is all that important- but the Thanks :-). And yes, I agree that these products are not particularly important for most current users of FreeBSD, who appear to be big users of 'dump' or afio. I do believe, however, that there is a potential market for an easy-to-use network tape backup product for small businesses and workgroups -- one that can be easily installed and configured by mere mortals without having to have a high-level Unix system administrator on staff. Obviously someone else agrees -- we have some venture capital for that. I managed to sell the idea of FreeBSD as a tier 1 platform to my management by using the spectre of backup appliances. Since my management is extremely Linux-centric (as you'd expect, given that we're owned by a Linux vendor), that was a pretty hard sale, but (shrug). What can I say, sometimes I like to use a real OS rather than a hodge-podge of tossed together software :-). > problem *has* been seen before... And, oh, btw, NetBackup ended up owned by > Veritas, not Legato, I believe ] I'm getting confused now. Let's see, Veritas is the former Seagate Software is the former software division of Archive Corporation? Or is that Legato? What do I know, I'm just an engineer :-). -- Eric Lee Green eric@estinc.com Software Engineer "The BRU Guys" Enhanced Software Technologies, Inc. http://www.estinc.com/ (602) 470-1115 voice (602) 470-1116 fax To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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