HP DLT 80 & Quantum 7000 compatibility

[Darrell Garvin_1]

I want to purchase a HP Surestore DLT80 device for my onsite backups (primarily
for speed). However I have to ensure that any backups taken onsite will be
recoverable at the disaster recovery site. At disaster recovery we use a
Quantum 7000 device (35/70Gb).

Can you confirm that I will, or will not, be able to use backups taken on a
Surestore DLT80 on the Quantum 7000 device. The cartridges I will be using are
DLT4 20/40 Gb.

Thanks
Darrell Garvin

P.S. this thread has been moevd from Archived Desktops and Workstations Boards > general to Tape Libraries and Drives - Hp Forums Moderator

[Bob Light]

Darrell,

The tapes made on the DLT 80 which has a DLT8000
mechanism in it are NOT readable by the DLT7000
but the tapes made by the DLT7000 SHOULD be able to be read by DLT80.

The DLT80 uses a different compression/recording format that is not available
on the DLT7000.

Bob

[Carlos Fernandez riera_1]

You can force DLT7000 compatibility creating a new device using mksf.

In this example I needed write in DDS1 and 512 bytes record format in a DDS3
driver.

mksf -C tape -b DDS1 -H 4/0.0.0 -s 512
mksf -C tape -b DDS1 -H 4/0.0.0 -s 512 -n

These commands create following devices:
/dev/rmt/c?t?d?s512DDS1
/dev/rmt/c?t?d?s512DDS1n
Use these device to create compatible tapes.

See mkfs and mt(7) man pages.

Goog luck.

[Carlos Fernandez riera_1]

Hello:

Usualy newer drives can read and write tape from older drivers (backward
compatibility).


In DLT drives there is a ' Density Select Button ' that allow the selection of
the desired compression.

If you want to read DLT 8000 tapes in a DLT 7000 drive, you must select 35.0 ,
compresion , and Density override when recording tape in DLT8000.

See the user manual of DLT.


I hope this line will be more usefull to you that my last letter.

Regards.

[Darrell Garvin_1]

Thanks for all the advice. I've already purchased a DLT 40 in order to be safe.
But I like the idea of being able to set the tape compression on a DLT80 to a
lower level.
At the moment all our DLTs are DLT 40 and offsite recovery is DLT7000.
Ideally I would like to transfer data between DLT80, DLT7000 and DLT40 devices.
Tape compression sounds good

Darrell Garvin

[Stone Stone]

Incompatibility of DLTtape(TM) cartridges written on a DLT8000, and then read
on a DLT7000, exists only if the the density is set to 40GB on the DLT8000.
For all other DLT8000 density settings, the DLT7000 is compatible with these.