Recently only getting 200GB on LTO3 tape

[asymantecuser]

Hi all

I need some help regading poor compression (in fact you might consider it expansion) on backups. 

Our environment: 2008 R2 server with BE 2010 R3 installed, connected to a Quantum Superloader 3 via SCSI. 

Problem:

Until now it's been working fine but weekend backups of 600GB are now looking for a third tape, which is ridiculous. 

We have the very same config above in other sites but can easily compress 600GB onto as little as one LTO3 tape. 

It's as if compression has suddenly stopped working. 

Testing:

Closer inspection and testing shows that we are only getting 200GB from the local server written to the tape. 

This is despite the job rate being between 1700\2000MB per minute, which is the norm. 

Other signs\symptoms: 

Under compression in the job properties were are using "Hardware Compression if available, otherwise none"

Under windows device manager > tape drives > driver > we are using the Symantec drivers loaded using tapeinst.exe

Backup to disk is not affected. 

Thanks

asymantecuser

[lmosla]

Hello,  Is this a duplicate to tape job? Is the media server ( and remote servers) up to date with Live Updates?  Is compression also enabled in the tape library interface?

[Donald_Eady]

Unfortunately backup exec doesnt really have any control over hardware compression outside of the request to do so. 

-You should begin by checking the tape/drive statistics to view Compression ratio and Read/Write errors "Hard/Soft"

-when was the last time the drive was cleaned? May need to be done

-You may want to see if there is a Diagnostic utility available "From H/W vendor" This is done outside of B.E. to confirm whether or not the equiptment needs servicing. 

- verify that the firmware is up to date

Additionally is this happening on all Tapes that are being written to and all jobs that target tape? If you have any news tapes you could load and target them.. Allow the job to run and verify as to whether you get the same results

[Larry_Fine]

If you cannot find other causes for your tape usage to change, you may have a clogged tape head, which reduces the useful capacity of a tape.

http://www.symantec.com/docs/TECH193200

[pkh]

1) To check that your hardware compression is working, create a small directory and fill it up with text files and back this directory up with hardware compression.  You should be able to see pretty good compression ratios.

2) Check that your tape library is listed in the Device Manager as an Unknown Medium Changer with a Microsoft driver.  If it has other drivers, change the driver using this procedure

How to uninstall the Original Equipment Manufacturer driver for the medium changer in a robotic libr...

3) It might be that there are some compressed files, like zipped or movie files, in your backup set. When you compress files which are already compressed, you might end up with more data than when you have started.  See my article below on this subject.

https://www-secure.symantec.com/connect/articles/compression-short-explanation

[MusSeth]

Is this happening with all tapes...have you checked with new set of tapes....

[asymantecuser]

Hi Imosla

No we do not use duplicate to tape jobs. 

I will need to check Live Update status although I doubt this will make a difference because it was fine a couple of weeks ago and probably just arose recently. 

Re compression - On the web interface for the Quantum Superloader 3 compression reads "Disabled" BUT this is normal and the case in all other 3 sites. Further reading tells me that this just means the use of compression is controlled by the backup software i.e. Backupexec

[asymantecuser]

Hi Donald, 

We're getting soft read errors, quite a few although this seems to be the norm in all sites for all tapes I have checked. 

The drive was cleaned yesterday.

I have tried running Quantums xTalk diagnostic utlilty but it won't see the drive. 

Suspect there is another issue causing xTalk problem. But yet I agree this is an essential next step. 

Re drive Firmware, yes this is up to date. 

Yes it's happening on new and existing tapes. I can't seem to avoid the problem by using certain tapes. 

[asymantecuser]

Thanks Larry, useful link. Because it is a remote site we are dealing with and end users are loading the tapes on my behalf, I'll have to double check some of the test tapes are BRAND NEW

I will also send out a brand new cleaning tape. 

[asymantecuser]

pkh, Thanks, It is using an Unknown Media changer driver. 

The nature of the data being backed up hasn't changed at all

[asymantecuser]

I need to confirm test tapes are BRAND NEW

[asymantecuser]

One other observation - Im getting as high as 1.7 to 1 compression on differential daily backups compared to 1:1 on weekend\test backups. 

[asymantecuser]

Since have got a new cleaning tape and cleaned the drive 3 times, in case of dirty tape heads, 

but the problem still exists. Going to speak to Quantum now to see why xTalk Diagnostics won't run. 

I imagine xTalk Diagnostics may give us some clues as to the problem. 

[CraigV]

...did you stop the BE services before running xTalk?

Thanks!

[asymantecuser]

Thanks CraigV

Yes I did indeed, that makes no difference, the error below still appears;

"No SCSI or SATA devices have been detected. Please inspect your system's cables and device terminators. Also, be sure you have installed the latest device driver for your tape product. If you feel you have received this message by error try rescanning the SCSI bus. You may need to close and restart the application."

(Rescanning the SCSI bus does hot help). 

I'm hoping quantum support know why this error occurs, because the diagnostics will be key to resolving the overall problem. 

[asymantecuser]

***** Turns out in server 2008 R2 you need to right click xTalk and choose "Run as administrator" in addition to stopping all Backupexec services first ***** 

xTalk diagnostics is now working and the device_health_check test shows an “LTO Error Rate Test  -------- : Failed”  error.

The Write_Read_FullTape test also shows that only xTalk can only too write about 200GB to a 400\800GB LTO3.

[CraigV]

...time to log a call with the vendor as there seems to be a compression error with the drive.

Thanks!

[asymantecuser]

Oh we have, I'm just writing it up here..... Cheers!

[Larry_Fine]

The Write_Read_FullTape test also shows that only xTalk can only too write about 200GB to a 400\800GB LTO3.

That still sounds like a clogged head, but the bottom line is that the drive probably needs to be replaced, which it sounds like you are working on.

[asymantecuser · Accepted solution]

As suspected the drive is faulty. We just had to prove it. 

A replacement drive is being shipped out....