12-03-2002
If each record is 60 bytes and you have 60 records per block, then each block is 3600. If you're writing to a disk file, the obs is irrelevant. It's the ibs which is critical. Although I would just use bs=3600.
Mainframes tend to have a concept called "labelled tape". The label will appear to you as a tiny file at the beginning of the tape. If your tape is labelled, you will get only one or two short records. Use the no-rewind device and if the dd gives you a very short file, run it again and you may get the real file.
You have ebcdic and you probably want ascii, so you will need to use conv=ascii on the dd statement.
9 More Discussions You Might Find Interesting
1. Solaris
I have two tape drives attached to my system , and i am trying to copy one tape to another using both tape drives and using the following command :
dd if=/dev/rmt/1 of=/dev/rmt/2
but unfortunitly i am getting the following error :
read: Not enough space
0+0 records in
0+0 records... (2 Replies)
Discussion started by: itsgeorge
2 Replies
2. UNIX for Advanced & Expert Users
Hi,
I' using a sun solaris server, I would like to known if there is the possibility to control how many space is free on a tape and how I can delete a single file on a tape.
Thanks
DOMENICO (3 Replies)
Discussion started by: Minguccio75
3 Replies
3. UNIX for Dummies Questions & Answers
Hi there: I'm new here
Can anyone help me:
I have DS15 Alpha server : Unix 5.1B
Now i need to connect a DLVT VS80 1U Rackmount Tape Drive unit.
What is the exact comman to mount the DLTape IV??
How do i make backuo @ copy file to the tape?
Thanx to all (0 Replies)
Discussion started by: ayzeayem
0 Replies
4. AIX
I am new to AIX. I want to make a duplicate tape. How can I do that ? (1 Reply)
Discussion started by: Anonno
1 Replies
5. UNIX for Dummies Questions & Answers
HI
I am recording some live music on my Sony Reel to Reel TC 366 and keeping the needles below the red but when I play it back the needles are way over in the red producing distorted sound. There is no volume out button on this model, just RCA out to my amp. Could it be a internal electronics... (0 Replies)
Discussion started by: jamt
0 Replies
6. SCO
when I do a tape status /dev/rStp0 I get the following on a new tape and I have tried several:
Status : ready beginning-of-tape
soft errors : 0
hard errors: 2
underruns: 5
My BackupEdge has stopped backing up my system because it asks for a new volume yet my total system data is under 20... (5 Replies)
Discussion started by: psytropic
5 Replies
7. AIX
Hello,
We need to make a copy of a backup tape, using the 2 tape recorders in IBM 3582 Tape Library
We tried tu use "tcopy", it seems to work fine (no error messages) but we aren't sure if we can rely on it.
my question is how to check if the copy succeded or not, but i also want to know... (3 Replies)
Discussion started by: fastlane3000
3 Replies
8. UNIX for Dummies Questions & Answers
I am using a 4mm tape to backup my Unix system. However, I wanted to make a copy all of the files and archive headers (or just the archive headers if that's possible) created on one of my tapes to another 4mm tape. I only have one tape drive. Is there a command that will complete such task? ... (1 Reply)
Discussion started by: acoco
1 Replies
9. AIX
I am trying to use this command to eject the tape
mt -f /dev/rmt/0 unload
but it gives me error
mt -f /dev/rmt/0 unload
mt: 0511-575 unload is not a recognized subcommand.
Usage: mt Subcommand
Valid subcommands are:
weof
eof
fsf
bsf
... (5 Replies)
Discussion started by: filosophizer
5 Replies
mt(1) General Commands Manual mt(1)
Name
mt - magnetic tape manipulating program
Syntax
mt [-f tapename] command [count]
Description
The command permits the operation of a magnetic tape drive.
Options
The -f flag option uses the specified tape device (next argument) in place of either that tape device defined by your TAPE environment
variable (.login or .profile) or /dev/nrmt0h.
Some operations may be performed multiple times by specifying count. By default, performs the requested operation once.
The command argument defines the operation to be performed. Only as many characters as are required to uniquely identify a command need be
specified.
The following is a list of commands:
bsf Backspace count files.
bsr Backspace count records.
cache Allows to use the cache buffer on a tape drive that has the cache buffer feature.
clhrdsf Clear hardware/software problem. Works with tape drives which use the TMSCP tape controller interface This command is
restricted to root access only.
clserex Clear serious exception. Works with tape drives which use the TMSCP tape controller interface
clsub Clear subsystem. Works with tape drives which use the TMSCP tape controller interface This command is restricted to
root access only.
eof, weof Write count end-of-file marks at the current position on the tape.
eotdis Disable end-of-tape detection. When the end of tape is reached, the tape will run off the reel. Only the superuser
can issue this command. The command remains in effect for the device until end-of-tape detection is enabled with the
eoten command.
eoten Enable end-of-tape detection. When the end-of-tape markers are reached, the tape is halted on the reel, between the
two end-of-tape markers. Only the superuser can issue this command. The command remains in effect for the device
until end-of-tape detection is disabled with the eotdis command. This is the default mode after a system boot.
fsf Forward-space count files.
fsr Forward-space count records.
nocache Disables the use of the cache buffer for any tape drive that has the cache buffer feature.
offline, rewoffl Rewind the tape and place the tape unit off-line.
retension Retensions the tape. Retension means moving the tape one complete pass between EOT and BOT.
rewind Rewind the tape.
status Print status information about the tape unit.
Examples
This example shows how to rewind the tape
mt -f /dev/rmt0l rewind
This example shows how to backspace the tape nmt1h three files:
mt -f /dev/nrmt1h bsf 3
This example shows how to write two end-of-file marks at the current position on tape nmt6h:
mt -f /dev/nrmt6h eof 2
Return Values
In shell scripts, returns a 0 exit status when the operation(s) were successful, 1 if the command was unrecognized, and 2 if an operation
failed.
Files
/dev/rmt?h or /dev/rmt?l
Raw magnetic tape interface with rewind when closed
/dev/nmt?h or /dev/nmt?l
Raw magnetic tape interface with no rewind when closed
See Also
dd(1), tar(1), ioctl(2), mtio(4), tms(4), environ(7)
mt(1)