Path: utzoo!utgpu!water!watmath!clyde!skep2!wcs
From: wcs@skep2.ATT.COM (Bill.Stewart.<ho95c>)
Newsgroups: comp.sys.att
Subject: Re: 3B20 Tapes
Message-ID: <170@skep2.ATT.COM>
Date: 30 Jun 88 23:00:49 GMT
References: <7600010@uiucdcsm>
Reply-To: wcs@skep2.UUCP (46323-Bill.Stewart.<ho95c>,2G218,x0705,)
Organization: AT&T Bell Labs Center 4632, Holmdel, NJ
Lines: 20

In article <7600010@uiucdcsm> carey@uiucdcsm.cs.uiuc.edu writes:
> Does anyone know if a tape written with volcopy on a 3B20 can be 
> read by a 3B15? (with volcopy or anything else)

Remember that a volcopy is a physical copy of the blocks in your
filesystem (basically "dd").  This means it will only be readable if 
	- your tape drive can handle the blocksize (some of the
		older tape drives for the 3B5/3B15 couldn't handle
		reading large blocks.)
	- it fits on the disk slice on the target machine (if the tape is
		smaller than the disk, you waste space but it works ok.)
	- you're running operating systems with compatible file system
		types - I think the 3B20 uses blocks of 512 or 1024,
		and the 3B15 uses 512 or 2048 - if the 3B20 tape has
		1024-size blocks you may be out of luck.  Check out the
		superblock headers and fs manual page.
-- 
#				Thanks;
# Bill Stewart, AT&T Bell Labs 2G218, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs
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