Compressing to a Tape Drive

neal at mnopltd.UUCP neal at mnopltd.UUCP
Thu Feb 14 08:42:30 AEST 1991


I gleaned the following sort of snippet of script from the i386 group to 
	make a cpio backup
	compress it
	increase the blocking to reduce the "shoe-shining" effect

find usr2 -print >> /tmp/bkup.names
cat /tmp/bkup.names | cpio -ocvB | compress | dd ibs=5120 obs=512k > /dev/rct0

However, it seems that dd cannot perform output to the tape drive under any
set of parameters without getting a write error on the last block.    

Even:
	dd ifs=/tmp/moo ofs=/dev/rct0
will generate a write error and, when copied back, the file will be missing
the last N hundred bytes.  (where N depends on the blocking factor)

(BTW: the drive and tape work fine with tar and cpio)  The drive is a Wantek
5150pk and I do have the software patch for it.    Have I blown my valves
or is there maybe a buglet here?


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Neal Rhodes                       MNOP Ltd                     (404)- 972-5430
President                Lilburn (atlanta) GA 30247             Fax:  978-4741
                             emory!mnopltd!neal 
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