| Title: | DIGITAL UNIX (FORMERLY KNOWN AS DEC OSF/1) |
| Notice: | Welcome to the Digital UNIX Conference |
| Moderator: | SMURF::DENHAM |
| Created: | Thu Mar 16 1995 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 10068 |
| Total number of notes: | 35879 |
G'day,
I have a customer who is trying to look at the record count on a
magnetic tape drive.
"I'm writing some code for real-time applications where we need to find
out the filemark count and record count on a magnetic tape drive.
Unfortunately doing 'mt stat' provides little useful information in
this regard:
...
Filemark Cnt <Not Valid> Record Cnt <Not Valid>
...
Looking at the devio(7) man page (I'm running this on OSF1 V4.0 -- ie
DigUnix v4 in an Alpha with either Exabyte or DLT tape drives) it
appears that there's a struct v1_tape_dev_info with the members
position and fm_count, which perhaps is what should get displayed
above?
Anyway, this is fairly important for us -- optimally we'd like to have
a command line facility (like mt stat!) that gives us the right
information, and also some system call that I can incorporate into the
C++ code, but the latter is more important..."
Any pointers/ suggestions/ideas would be greatly appreciated
Regards
Kym Schwarz
Unix support
CSC Sydney Australia
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 9823.1 | Not quite there on 4.0B | RHETT::PARKER | Thu May 15 1997 10:04 | 30 | |
Hi, Kym.
The v1_tape_dev_info is new to 4.0 and is in preparation for
SCSI 3 support, I think. In any event, I don't think it's quite
ready for prime time yet - here is the portion of the tape driver
that will (some day?) give us this info:
/*
* GREAT! :(
* we don't do anything to track filemark count or block count
* past last filemark.
*/
#ifdef not_now
if (!(ts_spec->ts_state_flags & CTAPE_POSITION_LOST_STATE))
tapep->media_status |= TPDEV_POS_VALID;
tapep->position = ts_spec->ts_records;
tapep->fm_cnt = ts_spec->ts_num_filemarks;
#endif /* not_now */
Maybe one of the experts will let us know when we can expect this.
Or, since it's documented, you could file a QAR requesting this info.
The customer I had that wanted it was ok with handling it from the
application so I didn't pursue it. I probably should have filed a QAR
anyway. If you don't IPMT/QAR, let us know and I will.
Hope this helps!
Lee
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