topic Re: Count of writing on tape in Operating System - HP-UX

Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 17:42:26 GMT

Hi,

I'd like to know, how i can find count of writing on tape. I know, there is possibility to use expert tool. However, I guess, it has to exist another way. :)

Ten points for right answer. :)

Thanks a lot

Radim

Re: Count of writing on tape

Jeff Machols — Tue, 11 Dec 2001 17:46:27 GMT

Radim,

Im not sure what you are looking for,but if you are using fbackup, you can do this.

Extract the index from the tape

frecover -I /tmp/index -f dev

There is field called Media Use that will tell you how many times the media has been used for a backup

Re: Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 17:52:14 GMT

Hi Jeff,

I want to find how many times I used to tape.

For instance. I have new tape and I use it every day and after month I need to know that the tape was used to 31 times.

Radim

Re: Count of writing on tape

Jeff Machols — Tue, 11 Dec 2001 17:53:30 GMT

Are you using fbackup/frecover?

Re: Count of writing on tape

Jeff Machols — Tue, 11 Dec 2001 18:01:45 GMT

If you are using frecover, just run

frecover -V /tmp/index_file -f device_name

if you look at /tmp/index_file the field called media use will show what you are looking for. If you are using tar or cpio or something like that, there is no way to tell

Re: Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 18:03:06 GMT

No. I don't

Re: Count of writing on tape

Jeff Machols — Tue, 11 Dec 2001 18:07:32 GMT

what do you use?

Re: Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 18:09:57 GMT

It doesn't matter,

For instance, I use tape for tar files,
next day for fbackup and next day for tar again.

Re: Count of writing on tape

Jeff Machols — Tue, 11 Dec 2001 18:14:19 GMT

The only thing you can do is setup a wrapper script around your backup and keep track of it yourself.

Re: Count of writing on tape

Darrell Allen — Tue, 11 Dec 2001 18:15:58 GMT

Hi,

You can't know how many times a tape has been written on. Some backup software (OmniBack for example) keeps track of how many times it has written on a tape. But it is possible to re-initialize tapes so that the backup software loses that count.

If you overwrite a tape with tar, dd, cpio, etc you will lose the count.

I suppose if you used new tapes, never wrote to them with anything other than your normal backup utility, and never re-initialized them you could get the count (providing the backup utility supported a count).

Darrell

Re: Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 18:29:17 GMT

Thanks for reply,

but today I saw this information in msmt tool.
Maybe I'm wrong, but ...
It looks I'll have to do it some script around my backup script, how jeff wrote me.

Re: Count of writing on tape

Darrell Allen — Tue, 11 Dec 2001 18:51:34 GMT

Hi Radim,

Would you please post what you did and saw related to:
<< but today I saw this information in msmt tool >>

I'm curious if this is something I've been missing.

Thanks,
Darrell

Re: Count of writing on tape

Raja_2 — Tue, 11 Dec 2001 19:00:31 GMT

So,

Today I had hardware problem with my DAT. The guy from hp support used mstm tool and showed me information, how many times i used my tape.
he also said me that it special tool in msmt, which can test tape and show a lot of information about tape. I suppose that exists another way how to find this information.

That's all. :)

Radim

Re: Count of writing on tape

Thierry Poels_1 — Tue, 11 Dec 2001 19:43:29 GMT

Hi,

as far as I know there is no tool to check how many times a tape has been used; I don't even think this is possible.

fbackup records times used on the tape. But as soon as you use another utility (tar, dd, ...) the fbackup header will be gone, and a next fbackup will start counting from 0 again.

regards,
Thierry.

Re: Count of writing on tape

Darrell Allen — Tue, 11 Dec 2001 20:59:57 GMT

Hi again,

I hope someone will correct me if I'm wrong, but I just don't believe there is any way to load a tape and tell how many times it has been written to. Further, even if there are utilities that read a header from the tape and re-write it, the header would be lost if the tape was demagnetized.

How about following up with the HP person who ran mstm and let us know what he says?

Thanks,
Darrell

Re: Count of writing on tape

Deshpande Prashant — Tue, 11 Dec 2001 21:09:58 GMT

HI

The omniback software tracks the write count on a media, since it was last initialized.
You can initialize the media to reset the counter.

Thanks
Prashant.

Re: Count of writing on tape

Michael Tully — Tue, 11 Dec 2001 21:44:25 GMT

Hi,

I've never heard of such thing. There are
only two proprietry backup products on
HPUX that will give information how many
times a tape has been used. The first is
'OmniBack', as long as the tape has not been
re-initialised, and the second is 'fbackup'
again as long as it has not been overwritten
by using a different tool. Only OmniBack will
not allow a tape overwrite be default.

HTH
-Michael

Re: Count of writing on tape

Printaporn_1 — Wed, 12 Dec 2001 02:58:39 GMT

I don't think that diagnostic tool (xstm,mstm,cstm) can report How many time that tape has been overwrite ?
May be just mis understanding of number of test loop.
Without backup tools that can trace this info.
Noway to know , we have to record in paper.

Re: Count of writing on tape

Vincent Farrugia — Wed, 12 Dec 2001 08:14:39 GMT

Hello,

This can't be done through software for the simple reason that this information is not stored on tape. Fbackup stores this information on tape, but this area is from the BOT onwards, not before. In order for this to be possible, this information needs to be stored before the BOT (Beginning Of Tape), where very important information is usually stored. Since this is not very important information (sorry!), then it's no use storing it there. There is a method to tell how many times the tape has been used though; the good-old tick-on-paper method. Get some stickers and tick on it whenever you make a backup. We do this for the cleaning tape media after all...

HTH,
Vince

Re: Count of writing on tape

Volker Borowski — Wed, 12 Dec 2001 11:16:34 GMT

May be I am completely wrong, but....

... for DDS : Yes there is !

Unfortunately, I do not know how.
I had a HP technican here some years ago, who said the same thing about a DDS/1.

I tried to search the web today, but I was not so lucky, may someone else is more. I found this:

http://www.compaq.com/products/storageworks/dat8cassette2040/qa.html
Where esp. the following section is interesting:
>>>>>>>>>>
Q: How many times can I re-use a tape?
A: The tape drive logs how many times the tape has been used during the eject process. Your application should read this count from the tape log and refuse to accept the tape after 99 uses. We recommend that regularly used tapes should be replaced annually as a precaution.
>>>>>>>>>
... but how to read that tapelog ?

And more interesting this one, as it is referncing HP tapes:

http://www.datman.com/tbul/dmtb_035.htm

Where it is explained, that after a "load" of a DDS tape, the tape is positioned some step "ahead" a special header. But I was never able to verify those two statements.

At least, I am sure, there is a tape section on the DDS media, that can not be accessed by application. That would explain, why this information is only readable from the tapelog, because the tape itself has only access to this information, when the tape is ejected.

I have to admit, I never thought about it, but if someone finds out how to read the tapelog, please let us know.

Volker