Frozen Media in NBU6.5.5

[Vikas_Mohila]

I have approx 4000 frozen media in my NBU6.5.5 environment running on SUN-OS. is there any way to differenctiate which media are actually damage and which are done by drive and could be of use.

vikasmohila@gmail.com

[Andy_Welburn]

You could look in /usr/openv/netbackup/db/media/errors - it may give you something to go on as it should show which drive was involved (I think! Am at home so cannot check directly)

Have you had a lot of "drive down" issues - maybe a specific drive or drives are causing these frozen media?

Are they write-protected?

Maybe they've been dropped & the tape-leader has dis-lodged or the case has eased apart?

Do you know how old they are? Maybe time to replace?

[Andy_Welburn]

you may find the following of use:

DOCUMENTATION: How to troubleshoot frozen media on UNIX and Windows
http://www.symantec.com/business/support/index?page=content&id=TECH21473

Can you confirm that your drive configuration is correct. If it isn't then NB can get "confused" & will freeze tapes if they are loaded in the "wrong" drives. e.g. if NB thinks your drive 1 is drive 2 then when a tape is loaded in both drives they will be "incorrectly" labelled as far as NB is concerned & so will subsequently be frozen.

This will probably explain better & how to use robtest to check this:

GENERAL ERROR: Tapes are being frozen due to "<16> write_backup: incorrect media found in drive index" errors.
http://www.symantec.com/business/support/index?page=content&id=TECH38936
  

Steps to verify device configuration using robtest.
http://www.symantec.com/business/support/index?page=content&id=TECH29201

[mph999]

6000 tapes is a lot, Andy gives excellent advice.

Just to add a little ...

If it were a config issue, this could freeze many many media as NBU just loops through the media, gets a failure, moves to the next, fails etc ...  In th /usr/openv/netbackup/db/media/errors you would maybe see these media erroring arund the same time.  If many media do this, then I suspect not faulty media.  However, if the overall environment is running fine, and each drive/ media server pair is not freezing every media, and, you have not made any config changes that could have fixed a previously broken config, then it may not be this.

This file /usr/openv/netbackup/db/media/errors, is on each media server, so you would have to dig about
 a bit.  I have a script that will statistiaclly analize this file, and may show some clues or patterms on which media has errored in which drive etc... If you send me the /usr/openv/netbackup/db/media/errors files I'll have a  look - mail me at martin <underscore> holt@symantec.com

Martin

[Vikas_Mohila]

Hi Martin,

Thanks for your suggestiong. I am sending you errors file. analyze and suggest needful. Thanks

[Andy_Welburn]

- be nice to see that.

[Vikas_Mohila]

andy would be grateful if I can get the script at vikasmohila@gmail.com

[Andy_Welburn]

I was just quoting his post & saying that it would be nice to see the script!

[Stumpr2]

Are there any valid images on the media?

[mph999]

The script will hopefully appear soon.

OK, guess my cover is blown ... he he ...  I'm working with a UK BL engineer to roll it out to the internal TSEs in EMEA to start with, and then hopfully the US.

The plan is then to introduce some partners to it and get some feedback to start with, then hopefully make it available externally, most likely via a Technote.

One or two customers do have it unoffically on the understanding that it is unsupported, I need to tidy a few odds and ends up but once I have I don't mind making it available to others here on the understanding that if there are any issues, I'll fix them as soon as I can, but it might not be immediate.

Here is a taster of the output ...

A23441 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)
A02182 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)
A01606 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 2)
A00652 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 4)
A00571 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)
A27060 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)
A02276 has had errors in 3 different drives   (Total occurrences (errors) of this volume is 15)
A01274 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 3)
A00149 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 3)
A31165 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)
A30373 has had errors in 1 different drives   (Total occurrences (errors) of this volume is 1)

TAPEDRIVE_007 has had errors with 1 different tapes   (Total occurrences (errors) for this drive is 1)
TAPEDRIVE_4 has had errors with 6 different tapes   (Total occurrences (errors) for this drive is 7)
TAPEDRIVE_009 has had errors with 4 different tapes   (Total occurrences (errors) for this drive is 4)
TAPEDRIVE_25 has had errors with 4 different tapes   (Total occurrences (errors) for this drive is 26)
TAPEDRIVE1 has had errors with 19 different tapes   (Total occurrences (errors) for this drive is 22)
TAPEDRIVE_019 has had errors with 1 different tapes   (Total occurrences (errors) for this drive is 1)
TAPEDRIVE3 has had errors with 62 different tapes   (Total occurrences (errors) for this drive is 91)

Or media specific ...

The drives that had an error with media A02276 also had errors with the following other media  ...

NetBackup Drive - TAPEDRIVE_007
  A02276 (       1)
NetBackup Drive - TAPEDRIVE_010
  A02276 (       1)
  A07399 (       1)
  A25624 (       1)
  A28473 (       1)
  A29503 (       1)
  A29982 (       1)
NetBackup Drive - TAPEDRIVE_25
  A02276 (      13)
  A22799 (       1)
  A23686 (       1)
  A25624 (      11)


Or drive specific ...

The tapes that had an error in drive TAPEDRIVE3, also had errors in the following other drives ...

Media - A29399
  Drive - TAPEDRIVE_002 (       1)
  Drive - TAPEDRIVE_004 (       1)
  Drive - TAPEDRIVE1 (       2)
  Drive - TAPEDRIVE3 (       1)
Media - A00032
  Drive - TAPEDRIVE3 (       2)
Media - A00043
  Drive - TAPEDRIVE3 (       1)
Media - A00149
  Drive - TAPEDRIVE3 (       3)
Media - A00202
  Drive - TAPEDRIVE3 (       2)

Martin

[Vikas_Mohila]

Yes, media have valid images on it

[Stumpr2]

I would run bpverify on the media which will mount the tape, read the header and verify that the images that the catalog says are supposed to be on the media actually can be accessed. It won't do a bit by bit check but it will verify the basic integrity of the tape. You can also run the verify from the GUI.