Getting frequent media frozen (around 100 tapes)

[A_3]

Master/Media - Linux ( NetBackup-RedHat2.6.18 7.6.1.2 )

I have unfreeze all the medias (3 days before) but again today i am seeing around 40 tapes are frozen.

Pls suggest

[DigPVB]

If there is no other data written to these tapes, it would not report that there is already data written on it, and it would not report this data as having ANSI format.

Please proceed by following the recommendations that Marianne has taken the time to write down for you, and verify whether these tapes are not containing any needed data, or are not 2nd hand/old. If the tapes are good to use, you can overwrite them.

[Marianne]

Please note that the media-id's that were identified in bperror output is only part of problematic/frozen tapes. 

You can adjust the bperror timeframe (or use Tape Logs report) to go back up to 28 days to find media errors. 
28 days is the default 'Days to keep logs' setting.

[A_3]

Sure Marianne: I will look into what all steps you have guided.

Media Performance Degraded, Data Is At Risk --- For this just removing tapes from library ? Not useable ?

[Marianne]

The error message certainly points to faulty/old tapes.

How old are these tapes?
How long have they been in the environment?

And your tape drives?

I notice that you have not shared any information about your environment and hardware/software details... 

[A_3]

@Marianne: I was in long leave.... Sorry for late reply.

I want to keep these tapes under observation as per management instruction. I will keep you udpated on this.

[A_3]

@Marianne: For ANSI tapes. I have done your given steps.

1. In Host Properties -> Media Servers (select Master server) -> Media -> Allow Media Overwrite:                                                                                                                                              Select ANSI.

              Click OK.

NBU services need to restart ?  Since i have done this before 2 days. Today again i recived same error.

How can I proceed next ?

[Marianne]

My mistake... for some reason I thought you had a single master/media server.

The ALLOW_MEDIA_OVERWRITE must go on ALL media servers.
No need to restart NBU.

Please post new output of bperror commands.
The output will list name of each media server that encounters media error.

[A_3]

I have done in all media server in GUI....now

Also tell me how many max mount for tapes ? Here i can see around 2000, 3000 mount count. 

[mph999]

Max mounts is difficult ... I had a long talk with Imation (who used to make very very good tapes) about this.

They eventually conclued that the number of mounts, was not a very good indication of tape condition - because it's not the mount that causes a problem, it's how the tape is treated once it is mounted.

Or in plain English - I could take a brand new tape, and within a couple of weeks wreak it by mis-treating it and it could be showing failures within 20 or 30 mounts

I can then take another new tape and treat it well (making sure it is written >streaming speed etc ) and it could be performing perfectly well in 3 or 4 years time after 1000's of mounts ....

Indeed, looking at the IBM site, they claim 20000 load/ unload cycles (not sure who make IBM tapes, it's not IBM, either Fuji or Sony as a guess).

So, in summary - it is a value your company and management must decide on, not a value you get from a forum.

[Marianne]

When you start getting TapeAlerts such as 0x04: 'Media Performance Degraded, Data Is At Risk', then you know it is time to remove those tapes from the environment.