mark@bruce.oz (Mark Goodwin) (09/08/88)
Why oh why doesn't tar work? Is this a SR9.7 type "feature" or do I have
to do something totally un-unix-like to /dev/rct8 so that tar can open it?
"/com/edmtdesc /dev/rct8 -L" prints :-
Volume information:
DEV (device type) CT
U (tape unit #) 0
LAB (labeled) no
REO (reopen previously used volume) yes
CLV (close volume on file-close) yes
SPOS (save position on volume-close) no
File information:
F (file sequence #) current
RF (record format) F (fixed length)
BL (block length) 512
RL (record length) 512
ASCNL (ascii newline handling) no
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Any help appreciated!
Mark Goodwin.GBOPOLY1@NUSVM.BITNET (fclim) (09/09/88)
sometimes the following works and sometimes it doesn't :
[hopes this is fixed in sr10]
first you need to log on or crp on or telnet onto the node
that has the
cart drive. then you must ensure that the tape is rewound. use
"/com/rbak -dev ct -rewind". now try "tar -f /dev/rct8 ...."
if the above doesn't work, i do
log on node. (no need to rewind tape)
/com/rwmt -dev ct -f 1 -rf f -unlab -r -raw -rl 512 -bl 512 file_1
tar -f file_1 ...
if you have a few tarfiles on tape, then change -f 1 and file_1 to -f n
and file_n respectively.
another method is
log on node and *rewind* tape
dd if=/dev/rct8 | tar -f- ....
i found out that i cannot make tar tapes at sr9.7. some guru told
me that i have to use a blocking factor of 1 (slllooooowwwww). so
i do the following:
tar -cvbf 1 file_1
log on node. (no need to rewind tape)
/com/rwmt -dev ct -f 1 -rf f -unlab -w -raw -rl 512 -bl 512 file_1
i also found out tapes make on non-apollo cart drives need not be
done with a bf of 1 (could still use default of 20), but apollo
cart drives must read and write at a bf of 1.
i hope this helps. beaucomp of lucks.
fclim --- gbopoly1 % nusvm.bitnet @ cunyvm.cuny.edu
computer centre
singapore polytechnic
dover road
singapore 0513.rees@MAILGW.CC.UMICH.EDU (Jim Rees) (09/10/88)
Why oh why doesn't tar work? Is this a SR9.7 type "feature" or do I have
to do something totally un-unix-like to /dev/rct8 so that tar can open it?
You have to rewind the tape first, even if it's already rewound. Use "rbak
-dev ct -rewind". One of the (relatively few) big disappointments of sr10
is that tape is still mostly broken, although you can now use "mt rew" to
rewind.
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