Bug 171340

Summary: mt man page misdescribes fsfm and bsfm arguments
Product: [Fedora] Fedora Reporter: Need Real Name <kodis>
Component: mt-stAssignee: Jindrich Novy <jnovy>
Status: CLOSED RAWHIDE QA Contact: David Lawrence <dkl>
Severity: medium Docs Contact:
Priority: medium    
Version: 4CC: pknirsch
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Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: 0.9b-2 Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2005-10-25 10:24:17 UTC Type: ---
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Need Real Name 2005-10-20 21:34:51 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20050922 Fedora/1.0.7-1.1.fc4 Firefox/1.0.7

Description of problem:
The operation of the fsfm and bsfm arguments is mis-described in the mt man page. 

Version-Release number of selected component (if applicable):
mt-st-0.8-5

How reproducible:
Always

Steps to Reproduce:
1. Read the mt man page.
2.
3.
  

Actual Results:  The man page includes this description:

       bsfm   Backward space count files.  The tape is positioned on the first
              block of the next file.

... and similarly for fsfm.

Expected Results:  The bsfm description should say that "The tape is positioned on the first block of the previous file.", and that fsfm moves to the next file.

Additional info:

Even that description is a bit misleading, in that to re-read a tape file that you've just read requires a "bsfm 2" to return to the beginning of the just-read file.  Perhaps something brief description of how file marks are used in tape positioning would be in order.

Comment 1 Jindrich Novy 2005-10-21 06:35:12 UTC
*** Bug 171339 has been marked as a duplicate of this bug. ***

Comment 2 Jindrich Novy 2005-10-21 06:40:25 UTC
Could you please reformulate the bsfm and fsfm description without any
misleadings to let me fix the man page and send the fix upstream? Thanks.

Comment 3 Need Real Name 2005-10-21 15:10:46 UTC
I'd change the "backward space file mark" command to read:

bsfm
Backward space past count file marks, then forward space one file record.  This
leaves the tape positioned on the first block of the file that is count-1 files
before the current file.

The corresponding change to the "forward space file mark" command should
probably read something like:

fsfm
Forward space past count file marks, then backward space one file record.  This
leaves the tape is positioned on the last block of the file that is count-1
files past the current file.

Just for information, here's how the Solaris man page describes the operation of
the bsf and nbsf commands of the Solaris mt command:

bsf
Back space over count EOF marks.  The  tape  is  positioned on the
beginning-of-tape side of the  EOF mark.

nbsf
Back space count files.  The tape is positioned on the first block of the file.
This is equivalent to count+1 bsf's followed by one  fsf.

I find this description easier to read than the one in the current RH man page.
 Also, there's a difference in how many files are skipped between the bsfm and
nbsf commands.  Under Solaris, an "nbsf 1" moves to the start of the prior file;
under Linux, a "bsfm 2" is required to do the same thing.  The Solaris version
of this command seems more in line with what intuition would lead a user to expect.


Comment 4 Jindrich Novy 2005-10-25 10:24:17 UTC
fsfm and bsfm descriptions are now fixed.

Comment 5 Fedora Update System 2005-10-26 17:21:18 UTC
From User-Agent: XML-RPC

mt-st-0.9b-1.fc4 has been pushed for FC4, which should resolve this issue.  If these problems are still present in this version, then please make note of it in this bug report.