SUMMARY: old tape backups..(a bit late..)

From: selcuk karaca (selcuk.karaca@aski.gov.tr)
Date: Thu Jan 08 2004 - 07:27:40 EST


Thanks to
Alan Rollow..
Russ Schaefer

Firstly, I will try to find a company which transfers data from old tape to
new ones..
If not I will try to get an old DLT35/70 or better, a TZ87 drive and will
transfer the data to new ones..

I will put Alan Rollow's answer here.. Because it is valuable for use..

I wouldn't expect any modern tape drive to be able to
read either the TK50 or TK70 (CompacTape II). If you
can find a working DLT 2000, DLT 4000 or DLT 7000
class drive, it should be able to read the CompacTape
IIIs. If you can find a TZ87N drive, it should be
able to read the older tapes.

You may be able to find older drives that can read
the older media; TZ50 or TZ30s, TK70s, TZ85s, etc.
But, you might be better off finding a company that
specializes in transferring data on older media to
newer media. They're likely to have working drives.

The information that I can find on the DLT 40/80
(TZ90, DLT 8000) says that it can can at least read
and probably write CompacTape III, so that's a pretty
good option for those tapes.

Last year I was able to buy a refurbished TZ89 (DLT 7000,
DLT 35/70) from HP (through a reseller) for around what
they're selling the 40/80. But, they not be selling them
anymore.

For what it is worth, transferring the data to new tapes
doesn't require understanding the format of the data that
is on the tapes. If the data on the VMS written tapes
were fixed record size, you could copy them with dd(1).
It probably isn't, since BACKUP most likely wrote ANSI
standard labels, which gives it a mixed record size of
80 bytes for the ANSI labels and something around 8 KB
or 32 KB for the data. tcopy, if still around might be
able to hand the changing record sizes.

As for the tapes, some background information:

TK50 - Digital's first generation DLT media. One serpertine
track worth about 95 MB of data. The media rate was slow,
around 45 KB/sec. Drives were built using SCSI and various
MSCP class interfaces. A low profile version of the drive
was built called the TK30.

TK70 - 2nd generation DLT media. TK70s could read TK50
written data, but I think only write native media. The
capacity and speed were improved. These may have used
multiple parallel serpertine tracks.

TK85 - 3rd generation DLT media. There were SCSI and
DSSI versions of the drives. This media supported three
native densities used by the Tx85, Tx86, and Tx87. The
85 and 86 variants were sold as the TZ8x (SCSI), TF8x
(DSSI) and TA8x (STI to a SCSI converter, making the back
end drive just a TZ8x. I think, but I'm not entirely
sure that the Tx87 was only sold in the SCSI (TZ87)
variety. The Tx85 and Tx86 were able to read all the
previous DLT formats. The N models of the TZ87 were
able to read all the previous medias. The native capacity
of the Tx85 was 2.6 GB with 600-800 KB/sec performance.
The Tx86 was 6.0 GB at probaby the same performance. The
native capacity of the TZ87 was 10 GB at 1.2 MB/sec peak.
The TZ87 also supported compression, which allowed higher
capacity if the data supported it.

CompacTape IV - 4th generation DLT media. This was used
by the TZ88, TZ89 and TZ90. It was around this tape that
Digital sold its tape business to Quantum, which relabeled
all the drives and media. The mappings are:

CompacTape III - DLTtape III
CompacTape IV - DLTtape IV

TZ87 - DLT 2000
TZ88 - DLT 4000
TZ89 - DLT 7000
TZ90 - DLT 8000

Vendors reselling the drives would rebadge as they saw fit,
often labeling with the native and assumed 2:1 compression
capacity:

TZ87 - DLT 10/20
TZ87 - DLT 20/40
TZ89 - DLT 35/70
TZ90 - DLT 40/80

There was an intermediate media between the III and IV, the
III XT. I think this was just a little longer, giving it
a native capacity of 15 GB.

After the DLT 8000 generation, Quantum went to the SuperDLT
(SDLT) drives and media. I don't know how far back in the
family tree those drives read.

My question was;

>
> Hello admins...
>
> My box is ;
> ES40 model, tru64unix V5.1 OS
>
> I have some (187 pieces..)
>
> CompacTape II
> TK50
> CompacTape III
>
> tape cartridges which are taken on VMS system.. I want to transfer these
> data to new LTO cartridges in tru64unix 5.1 system..
>
> My old DLT 35/70 tape drive is out of order now. It often lits "use
cleaning
> tape cartridge" led. I have used it to read -at least- compac tape III
> cartridges.. According to technical service, its head life exhausted..And
> calculated 10270$ cost to mend it..!! (In fact they will replace the inner
> part of the tape drive completely..)
>
> I have found DLT 40/80 tape drive (there is no DLT 35/70 drive in HP site)
> with 2600$ cost.. But I dont know if I can read my old tape cartridges
with
> it..!!!
>
> Moreover, I could not use vmsbackup freeware , So I will go with vbackup..
> Have you ever experience with vbackup..?
>
> Shortly, Can you guide me to read those tape cartridges..?
>
> TIA..
>



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