Very Computer

I am running SCO V3.2 release 4.2 using BackupEDGE software to backup to an
HP C-1533 4GB SCSI DAT drive.  The documentation for the drive indicates
that it performs hardware compression to put 8GB on a 4 gig tape. No matter
what I have tried, I cannot get more than 4 gigs on a tape.

Anyone have any ideas??

Chris

: I am running SCO V3.2 release 4.2 using BackupEDGE software to backup to an
: HP C-1533 4GB SCSI DAT drive.  The documentation for the drive indicates
: that it performs hardware compression to put 8GB on a 4 gig tape. No matter
: what I have tried, I cannot get more than 4 gigs on a tape.
:
: Anyone have any ideas??
:
: Chris

Difficult to say exactly but here are the guidelines:

1) You must be using a 120 meter tape.

2) The drive must be in compression mode.

3) BackupEDGE must be set NOT to compress.

4) Your volume size should be set at around 8GB (7944192 is our default).

You should download the SCOTAPE program from the Microlite Web Site
and run "scotape -report /dev/rStp0" (use your own device name if different).

Check for:
Switch Settings:  1 1 0 1 1 1 1 1
Tape Information: DDS 120m
Data Compression: Compress on Write, Decompress on Read

If SCOTAPE reports something different, let us know.
You may NOT get a full 8GB from the drive.
HP uncompressed capacity is AROUND 4GB depending on the tape,
and IF all your data can be compressed an AVERAGE of 50%, they
figure they'll call it an 8GB drive.
Some people get a lot more.
Some people get a lot less.

Let us know.

Below my signature is a sample SCOTAPE report from an HP drive.
Note that the "Remaining Tape" field is the result of a query
from the tape drive to the tape itself and represents the number
of UNCOMPRESSED megabytes the drive thinks it can write.

Tom
---
D. Thomas Podnar                     Microlite Corporation
Sales:    (800) 992-2827             2315 Mill Street
Support:  (412) 375-6711             Aliquippa PA  15001-2228
Fax:      (412) 375-6908             +----------------------------------+

WWW:      http://www.microlite.com   | Data Archiving Software For Unix |
FTP:      ftp://ftp.microlite.com    +----------------------------------+

Microlite Corporation      SCSI Tape Capabilities Inquiry Report  09/27/1996
============================================================================
Vendor:                         [HP      ]
Product Revision:               [9503]
Product ID:                     [C1553A         ]
Standards Conformance:          SCSI-2
Device Type:                    Sequential Access
Firmware Information:           Firmware Rev = 4.31      
Serial Number:                  (Unknown)
Max. Block Size:                16777215
Min. Block Size:                1 (0, Variable Supported)
Current Block Size:             Variable
Remaining Capacity:             3783 MB
Switch Settings:                1 1 0 1 1 1 1 1
Write Protect:                  Tape Is Write-Enabled
Speed:                          0
Tape Information:               DDS2 120m
Active Partition:               0
Setmark Recognition:            0
Early Warning:                  0
Data Compression: Compress On Write, Decompress On Read

Chris Mawdsley wrote

Quote:

>I am running SCO V3.2 release 4.2 using BackupEDGE software to backup to an
>HP C-1533 4GB SCSI DAT drive.  The documentation for the drive indicates
>that it performs hardware compression to put 8GB on a 4 gig tape. No matter
>what I have tried, I cannot get more than 4 gigs on a tape.

--

We have a 4/16 GB DAT drive from Compaq and the documentation was wrong.
It told us to change a dip switch at the on position and, somewhere else,
it was telling us to change the switch to off!  You might call HP to check
if you're experiencing the same problem.  BTW our Compaq drive is
manufactured by Archive and not by Compaq...