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Compression on DAT72

Roman Tobler
Occasional Visitor

Compression on DAT72

Hello,

I am using a C7438A DAT72 tape drive (firmware V601) with Veritas Backup Exec 10.0., on a Windows SBS 2003. It seems to me that I am not able to activate hardware compression. The Veritas App detects a DDS4 instead of a DAT72 drive (with its own driver). When I try to install an HP original driver I am also not able to choose compression in the setup window. In the tape tools support log hardwarecompression is disabled, but the drive passed the compression test.

Do someone know a solution of my problem????

roman
12 REPLIES
Johnrh
Occasional Contributor

Re: Compression on DAT72

You might want to check me on this but I believe the DAT72 can only read DDS4/3 tapes and you must have a DDS5 or DAT72 type tape to record. .... it may only stay in DDS4 mode when using a DDS4 tape.
Roman Tobler
Occasional Visitor

Re: Compression on DAT72

I am using DAT72 tapes, the problem is, that Veritas do detect these tapes as DDS4 tapes!

I tried to install the hp driver again and in the driver settings the value for compression capable is true but the value for compression enabled is false and I am not able to change these settings.

Normaly you have to configure compression via dip-switches but the switches are configured for compression enabled.

It seems to me that the driver settings and the hardware settings do not fit together; but I am not able to see the problem!

roman
LTT Team
Valued Contributor

Re: Compression on DAT72

Install L&TT and run Drive Configuration Test to enable the hardware compression. Similarly, let us know what L&TT displays in the Product ID page.

Note: Before running LTT ensure all backup services are stopped.

Download L&TT from,
http://h18006.www1.hp.com/products/storageworks/ltt/index.html
LTT Team
Valued Contributor

Re: Compression on DAT72

After selecting Drive Configuration test, click on Options and select enable for Hardware compression.
Remco Nienhuis
Occasional Visitor

Re: Compression on DAT72

hello,

i try the tape tools but still backup exec stops at 35 GB coudl anybody fix it?
Andrew Watts
Occasional Visitor

Re: Compression on DAT72

I'm having the same problem with Veritas Backup Exec 11d - compression resets itself every time Backup exec runs.

Veritas don't supply drivers for USB drives and say it's up to the tape drive to do the compression.

Can anyone shed any light on this?
Robin Sherwood
Occasional Visitor

Re: Compression on DAT72

I'm experiencing the same issue - my firmware is correct according to L & TT (at ZP5A) but it still appears that although hardware compression is enabled according to the software, it's not recognized for some reason by Backup Exec forhardware compression by the backup jobs.

So - can I conclusively identify hardware compression as working using L&TT so I can go back to Symantec (I'm on 10D) and get their assistance? HP moderators - please lend some assistance here (more specific than has already been offered?)

Like others in this thread, it seems this model drive and certain versions of BE are a "bad mix" at the moment...and this issue is unresolved.

Robin
kis.charles.russell
Occasional Visitor

Re: Compression on DAT72

Yes,

Here is the solution to the problem, atleast it was for me. I've had a couple techinicans work on this problem for one of our customers and they couldn't get compression enabled with this device and Backup Exec.

I removed all Symantec Drivers.
Rebooted the machine
Reinstalled the latest drivers for the device.
( THIS MIGHT NOT BE REQUIRED ) Perform the following tasks below for a potentially quicker answer...

Log into BENT
Click Devices.
Drill down to your tape drop, properties.
Configuration tab

Click DEFAULT.
Uncheck single block read/write
Make sure passthrough read/write is unchecked.
Change Block size to 64k
Change Buffer to 1024.

Run a erase.
Run a relabel.
Run a quick test back of a large ( 150mg ) test file to make sure it is working.

With a 105mg test file, it gave me 10.6:1 compression.


Side note. I know my device in the back up job is configuration for Hardware, software if not available for compression.


Have a good day, hope this helps.
Robin Sherwood
Occasional Visitor

Re: Compression on DAT72

Hi Charles - I'll look at your solution and let you know how it works for me! Thanks for keeping an eye out for this thread!

Robin
Andrew Watts
Occasional Visitor

Re: Compression on DAT72

Thanks for the response Charles - I went through the steps that you suggested but still no luck.
Marcus Freeman
Occasional Advisor

Re: Compression on DAT72

latest model DW027A - ZU75 firmware

LT&T reports 2.23:1 compression with 64MB test.

Windows driver is 1.5.3.2.

Backup Exec 11d. Compression Enabled. 64KB blocks, 1024KB buffer. results in 1.06:1 compression with 105MB test copy directory.
Kevin Bachar
Occasional Visitor

Re: Compression on DAT72

Did anyone ever get this to work? I downloaded the l&tt, ran the compression check. Got a 2-1 result.

I have the HP 1.7.0.1 driver.

I am running BE 12.5 sp2.

Yet I get no compression from BE. I have it turned on in the BE device settings and I tried the 64/1024 trick suggested.