DDS3 tape drive drivers

[Nivesh Patnaik]

I had to replace a DDS1 tape drive on a 725 system running HP-UX 10.20 with a DDS3 HP Surestore DAT tape drive.
Nothing other than a swap was done. The tape drive is usable.

I thought I should create new drivers for the tape drive.

When I use SAM, in the list for what density I want to use, amongst others I see BEST, DDS1 and DDS2. Should there be a DDS3 in the list (how do I get it?) ?

What density should I be using with the DDS3 tape drive so I can backup 12GB normal and 24GB compressed?

Thanks,
Nivesh

[John Carr_2]

Hi

In SAM if you select peripherals then tape drives what description does it give for the drive.

John.

[John Carr_2]

Hi

In SAM if you select peripherals then tape drives what description does it give for the drive.

you should also have the option here to select pull down menu action then create default device files.

John.

[Bill Hassell · Accepted solution]

There really isn't a density anymore (that went out with the old 1/2" reel-to-reel tapes). But old habits stick around in Unix so the density is still there. There are only two, uncompressed and 'BEST' density, which translated means: compressed

The device files are decoded with lssf as in:

lssf /dev/rmt/*

and again, the word BEST means compression will be enabled. For a DDS3 drive, there really isn't a 24Gb mode. Rather, it is a marketing pitch that translated means: If the data content can be compressed 2:1 then the tape will appear to hold 24Gb. Unless you verify the compressibility of every file and add up the results, there is no way to predict the actual storage capacity, except 12 Gb native is guarenteed.

The name of a device file (0m, 2mnb, DDS2, etc) does not cause anything special to happen. Instead, the two numbers (major and minor seen with the ll /dev/rmt command) select the dirver (major) and the options (minor). The driver is mostly aligned with the interface (SCSI, fibre, etc) and if you are reasonably up to date on patches, you won't need anything else to control the tape drive.

[Nivesh Patnaik]

Thanks Bill. That answers my questions.

[Helen French]

Hi Nivesh:

If you are using HP-UX 11.0, then install these patches:

PHCO_23876 - s700_800 11.00 cumulative SAM/ObAM patch ( this will support the new density drives - ultrim, dds3, dds4 )

PHKL_25769 - s700_800 11.00 SCSI Tape (stape) cumulative

HTH,
Shiju