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- Newsgroups: comp.sys.sgi
- Path: sparky!uunet!sun-barr!ames!sgi!fido!zola!zuni!anchor!olson
- From: olson@anchor.esd.sgi.com (Dave Olson)
- Subject: Re: dump parameters for various types of media?
- Message-ID: <pntk3hc@zuni.esd.sgi.com>
- Sender: news@zuni.esd.sgi.com (Net News)
- Organization: Silicon Graphics, Inc. Mountain View, CA
- References: <32536@adm.brl.mil>
- Date: Fri, 11 Sep 92 23:06:47 GMT
- Lines: 47
-
- In <32536@adm.brl.mil> mcdonald@aedc-vax.af.mil writes:
-
- | I was wondering how to set the various parameters in dump for the various
- | types of media (especially 4mm DAT tapes).
- |
- | What values should the following be set to:
- | Blocking Factor
- | 1/2" tape density 6250 BPI 64 ?
- | 1/4" cartridge 126 ?
- | 2.3-Gbyte 8mm ?
- | 4mm DAT ?
-
- Well, there are no absolutes, but there are our 'recommended' defaults.
- You can find these (for scsi tape) in master.d/tpsc. Note that the
- large sizes may not be readable on non-SGI machines (Sun's in particular
- have problems with larger than 64K -2 bytes.
-
- In general, you want something large enough to not cause overhead to
- predominate, but not so large that you aren't able to overlap tape
- and disk i/o. I'd recommend using at least 64 Kbyte buffers for
- all of the above.
-
- | Tape Density
- | 1/2" tape 6250 BPI ?
- | 1/4" cartridge 1000 BPI ?
- | 2.3-Gbyte 8mm 54000 BPI ?
- | 4mm DAT ?
-
- I'd use 54000 again, it is all bogusly calculated anyway.
-
- | Length(size) of Tape
- | 1/2" tape 2300 - 2400 feet ?
- | 150-Mbyte 1/4" cartridge 600 feet ?
- | 2.3-Gbyte 8mm 6000 feet ?
- | 4mm DAT ?
-
- I'd use 3350 for 60 meter (1.3 Gb), and 5200 for 90 meter (2.0 Gb).
-
- A future release will have an argument 'C' to dump that allows you
- to specify capacity in kbytes or mbytes, rather than requiring the
- d and s arguments.
-
-
- --
- Let no one tell me that silence gives consent, | Dave Olson
- because whoever is silent dissents. | Silicon Graphics, Inc.
- Maria Isabel Barreno | olson@sgi.com
-