The answer to the question is, YES. The utility vdump has the support
multitape. but is not recommended, because depending on the human factor,
the more recommendation is the use robots loaders of tapes.
Thank to all
Marcelo Alonso M.
The question is:
Any knows if the Vdump utility supports multitape (a file in several
magnetic tapes) or exists any utility that supports this characteristic in
tru64Unix. ?.
This is any comments:
Lavelle, Bryan <Bryan.Lavelle_at_COMPAQ.com>
It does as long as you are standing by ready to insert the next tape
cartridge yourself, OR your tape libary can do it for you, but most don't.
Richard L Jackson Jr <rjackson_at_gmu.edu>
Yes, if vdump reaches the end-of-tape, another tape is requested by vdump
and
the backup continues on the new tape.
Dr. Thomas.Blinn_at_Compaq.com <tpb_at_doctor.zk3.dec.com>
If you mean "does vdump know how to ask for another magtape or for
several successive magtapes if there isn't enough room on one tape
to hold an entire file", the answer is "yes".
If you mean "does this work really well", the answer is "no, not in
most cases, because there MUST be a human involved to arrange for
the tape swap and answer the questions from the utility".
If you are looking for something that will help you transfer large
files from Tru64 UNIX to some other system, vdump isn't it, since
no other vendor's system understands how to read a vdump tape, and
"tar", "pax", and "cpio" are not great at handling multiple tapes,
either, although they do have some support for doing so; as far as
I can recall, the support in "tar" was broken the last time I tried
to use it, and the people who are responsible for fixing bugs in it
are as likely to break it as to make it better.
You can, in principle, use "dd" for this, as well, although you have
to decide where to break the file apart and then figure out how to
put it back together again.
Davis, Alan <Davis_at_tessco.com>
Yes, vdump will handle multiple volume backups. You will need the robot
utiility or custom-written scripts to manage the tape loader. The robot
utility is a separately licensed utility (included in some other products,
like Legato Networker) that requires the SCSI CAM Layered product. The CAM
drivers are a separate setld kit for v4.x but have been included in the
base
OS for v5.x.
Here's the SPD for robot :
http://www.compaq.com/info/SP6444/SP6444PF.PDF
alan_at_nabeth.cxo.dec.com
I have read, but never verified that vdump will send an
"offline" command to a tape drive when it reaches EOT
(and finishes a backup, unless the norewind device is
used). On sequential loaders, this will cause a tape
change. If vdump also waits a reasonable amount of time
for such a change to take place and verifies that the
tape present in the drive is not the same one that it
previously wrote to, it could handle tape changes in this
limited space.
I don't know that it does this and I wouldn't make a backup
assuming that it did. However, it might be worth checking
if you have a sequential loader.
Generally, if you want media management, even if you only
need primative media management, you need to get a backup
product that supports media changers. If you have such a
changer or library, I have heard of people that write
expect scripts to run their backups. The script will
intercept the prompts for tape changes and use whatever
tools are available to change tapes. For sequential
changers mt(1) with the "offline" command is sufficient.
For random access changers, MRU is often sufficient.
It might also be possible to write a program which reads
data from stdin and writes to a specified tape devices or
devices. It can recognize the need for tape changes and
handle them as desired. This is a fairly complex solution
to the problem but allows the most customization. Most
backup utilities will allow writing to stdout:
vdump 0f - /file-system | blocker /dev/nrmt0h ...
Received on Mon Apr 02 2001 - 21:54:51 NZST