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Subject: bin/20725: Raw floppy writes fail for partial bytes.
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>Number:         20725
>Category:       bin
>Synopsis:       Raw floppy writes fail for partial bytes.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Aug 20 03:20:01 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Mike Meyer
>Release:        FreeBSD 5.0-CURRENT i386
>Organization:
Missionaria Phonibalonica
>Environment:

	-current updated and built as of Aug 19, ~ 3am PDT.

>Description:

	It appears that partial block writes to a floppy disk are failing.
	This means that writing an arbitrary sized binary (like the second
	stage of the grub boot loader) to disk fails to write the last
	partial sector.

>How-To-Repeat:

	Find a file smaller than a floppy that has a size that is *not* evenly
	divisible by 512 (making it an odd number is probably best; I did not
	try sizes smaller than 512 bytes), and try copying it to a floppy via
	either:
	
	cat TESTFILE > /dev/fd0
	dd if=TESTFILE of=/dev/fd0 bs=512

	and observe the error message. dd is more informative, as it
	shows that the last partial write is what failed.

>Fix:

	Well, I work around it by padding files - but that shouldn't
	be required.


>Release-Note:
>Audit-Trail:
>Unformatted:


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