pkg/34536: TME sometimes truncates files when reading via emulated tape drive

[sigmfsk%aol.com@localhost]

>Number:         34536
>Category:       pkg
>Synopsis:       TME sometimes truncates files when reading via emulated tape 
>drive
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Sep 15 19:10:00 +0000 2006
>Originator:     Arthur Townsend
>Release:        3.0
>Organization:
>Environment:
3.0 for i386
>Description:
When reading files into the emulator via the emulated tape drive (issuing: 
command tape0 load foo.tar at the tmesh prompt, then tar xvf /dev/nrst0 inside 
the emulator), the last section of data in the tar file is sometimes/usually 
truncated.
>How-To-Repeat:
Create some files, put them in a tar file.  Read in the tar file, then do a 
"sum" on the original files, and the files loaded into the emulator 
environment.  Sometimes the last file will be missing, sometimes the last file 
will have a different checksum.  I was able to duplicate the problem with the 
following operating systems inside TME: NetBSD 1.5.3, 1.6.2, 3.0, and SunOS 
4.1.1 and SunOS 4.1.1U1.  Some versions seemed to truncate the files more often 
that others, but all had problems.
>Fix:
Workaround:  Always stick a junk file at the end of a tar set so when it is 
truncated, it doesn't matter.  Do a checksum on all extracted files to ensure 
they are correct.  Easiest way is to get all the files to go inside the 
emulator and put them in a tar file.  Then tar up all the tar files.  ex:  to 
load one.txt and two.txt:  tar cvf a.tar one.txt two.txt;  cp a.tar junk.tar;  
tar cvf b.tar a.tar junk.tar;  command tape0 load b.tar; tar xvf /dev/nrst0 - 
then a.tar and junk.tar will show up in the emulator.  in the host environment 
and target emulator environment, sum a.tar junk.tar.  the sum for a.tar will 
match and junk.tar won't.  delete junk.tar inside the emulator, then tar xvf 
a.tar inside the emulator and the resulting files will be correct.