[NTLUG:Discuss] OT: tar question

[Fred James]

All
[not entirely OT - it is tar used on Linux]

[Operation]
Within a BASH script, called by cron, I am using 'tar -cvf ...' (tar 
(GNU tar) 1.13.25) to write to a DLT tape, supposedly capable of 35 GB 
in non-compressed mode, which is what I am doing.

[Problem]
At somewhere between 4.1 and 4.2 GB, I start losing things.
I capture a log of files as they are written to the tape, and then I 
write a second log using 'tar -tvf ...', and compare the two files.  I 
am finding that somewhere above 4.1 GB of data, some file or two will 
not be in the second list.

I used to run into this on SGI (see snip from man page below, from SGI 
IRIX 6.4) for files greater than 2 GB, but I don't see any mention of 
this problem in the man page for GNU tar 1.13.25.

Thank you in advance for any help you may be able to offer.
Regards
Fred James

[snip from SGI man pages for tar]
     K     Required for files larger than 2 Gigabytes.  Tar will issue a
           warning and skip such files if an attempt is made to archive them
           without the K option.  Mutually exclusive with the O option.
           Warning: Use of this option may result in the creation of an
           archive that is not portable to other 
machines.