Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!dogie.macc.wisc.edu!uwvax!rutgers!att!cbnews!maddog
From: maddog@cbnews.ATT.COM (john.j.tupper)
Newsgroups: comp.sys.hp
Subject: Re: tcio(1)
Keywords: tcio command, HP9144, HP-UX
Message-ID: <6377@cbnews.ATT.COM>
Date: 8 May 89 20:58:37 GMT
References: <2105@litp.UUCP>
Reply-To: maddog@cbnews.ATT.COM (john.j.tupper)
Organization: AT&T Bell Laboratories
Lines: 36

In article <2105@litp.UUCP> pda@litp.UUCP (Pierre DAVID) writes:
>- from the documentation, I understand that "-S <n>" specifies
>  the size of memory allocated by "tcio" for its use and is without
>  relation with the physical encoding on the tape. However, I have
>  noticed tapes written with -S 8 that could not be read again
>  without this option.
>
>- I have a similar problem with the "-Z" option. From the documentation
>  I understand that this option allows a binary copy. So, for example,
>  a tape written directly (by "tar(1)", for example) can be restored
>  using "tcio ... -Z ... | tar ...".  My attempts have been stopped by
>  a "tcio" hang, even "kill -9" doesn't work.

The -S option only affects the amount of data transferred across the hpib
in a single write, the data is stored on thap the same regardless of what
-S size you use (well, almost). I can write/read tapes with different -S
sizes, perhaps you have a bad tape.

I have found that if I don't use the -e switch when writing tapes, I can have
trouble reading them back (-e write an end of tape mark after your data).
Seems especially true when used with cpio (you get extra garbage from the
end of the tape and cpio chokes).

It sounds like what you want is "tcio -oZVeS 8 /dev/???".
	Z - don't waste the first and last block for tcio overhead
		(you may get in trouble if your data won't fit on a single
		tape. I've never tried it).
	V - don't do a verification pass. The 9144 doesn't need it as it
		does a read while write.
	e - write a tape mark at the end of the data.
	S 8 - block size.

You may also want to check out /usr/include/sys/cs80.h for some undocumented
ioctl calls to control the tape (look at the end of the file).
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