One feature of DLT that is often touted is the quick retrieval of data from
the tape. It is supposed to be able to determine which logical track the
desired file is located on, and go there directly rather than searching
serially through the entire cartridge. For a while, I believe MPE did not
support this feature, but later did. Is this capability implemented within
the DLT hardware, or does the driver on the host get involved in the
process? How is that information stored/retrieved?
-----Original Message-----
From: Denys Beauchemin [mailto:[log in to unmask]]
Sent: Wednesday, January 15, 2003 11:15 AM
To: [log in to unmask]
Subject: Re: Life of DLT tapes?
I would doubt very much that FOS Store knows anything about what is
happening on the tape itself. The medium itself would need to keep track of
the number of passes and be able to send this count back on a SCSI command.
The LTO Ultrium 1 tape has a chip in the cartridge itself that accumulates
information. I also doubt there is anything in the SCSI command set that
would inform a program that the tape has just completed one logical track
and is now starting on the next one. As far as the calling process is
concerned, the tape drive simply responded back that the write (or read) was
done with no problem and not EOT encountered.
Denys
-----Original Message-----
From: Tracy Pierce [mailto:[log in to unmask]]
Sent: Wednesday, January 15, 2003 12:55 PM
To: [log in to unmask]; HP3000-L (E-mail)
Subject: FW: Life of DLT tapes?
sorry. That's a very comprehensive site, Denys, and rather than read the
whole thing, I did a quick search of the site (and google) and found several
claims of 1,000,000 passes MTBF, nearly incredible!
But it appears that there's likely a large number of passes per backup. Is
there any way to figure out or even guess just how busy the tape really is,
pass-wise?
I know that FOS STORE is somehow aware of what's actually happening with the
tape; I'm wondering if there's a way to get something like a rewind count or
similar so that the tapes can be realistically re-used until they're
expected to be tired.
Tracy Pierce
-----Original Message-----
From: Tracy Pierce
Sent: Wednesday, January 15, 2003 10:32 AM
To: [log in to unmask]; [log in to unmask]
Subject: RE: Life of DLT tapes?
Is there a way to COUNT the 500,000 tape passes?
> -----Original Message-----
> From: Denys Beauchemin [mailto:[log in to unmask]]
> Sent: Wednesday, January 15, 2003 10:32 AM
> To: [log in to unmask]
> Subject: Re: Life of DLT tapes?
>
>
> www.dlttape.com will have lots of information for you. One thing to
> remember is that when they talk about number of passes
> (500,000 passes), it
> does not mean number of tape mounts.
>
> Denys
>
> -----Original Message-----
> From: HP-3000 Systems Discussion
> [mailto:[log in to unmask]]On Behalf Of
> Maureen Kammerer
> Sent: Wednesday, January 15, 2003 11:59 AM
> To: [log in to unmask]
> Subject: Life of DLT tapes?
>
> Does anyone know the recommended life or max usage of DLT tapes?
>
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