On Aug 20 14:56, Pim Zandbergen wrote: > >>mt -f /dev/st0 setblk 16384 > >>dd if=/dev/zero of=/dev/st0 bs=16k count=1
Thanks for the simple testcase :-) Actually we have two problems in one here. The first is that your above `dd' statement should not work! See on Linux: $ mt setblk 16384 $ dd if=/dev/zero of=/dev/st0 bs=512 count=32 dd: writing `/dev/st0': Invalid argument 1+0 records in 0+0 records out The reason is that writes on tape devices must always be in multiple of the blocksize set in the device driver. So, only that should work: $ dd if=/dev/zero of=/dev/st0 bs=16384 count=1 1+0 records in 1+0 records out or, FWIW, that: $ dd if=/dev/zero of=/dev/st0 bs=32768 count=1 1+0 records in 1+0 records out Note that it's the same on Windows. WriteFile calls on raw devices must write in multiples of the blocksize set in the device driver. So far so good. Unfortunately, the first `dd' statement really didn't return. I've debugged it and found that the low level tape write function in Cygwin missed to return -1 on error. As a result, the write(2) call returned 0 instead of -1 to the calling function in `dd', even though the Win32 WriteFile call returned an ERROR_INVALID_PARAMETER. I've fixed that in current CVS. So the next Cygwin version has the same behaviour as Linux: $ dd if=/dev/zero of=/dev/st0 bs=512 count=32 dd: writing `/dev/st0': Invalid argument 1+0 records in 0+0 records out $ dd if=/dev/zero of=/dev/st0 bs=16384 count=1 1+0 records in 1+0 records out Again, thanks for the testcase, Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader mailto:[EMAIL PROTECTED] Red Hat, Inc. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
