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OnRappell's avatar
OnRappell
Level 3
11 years ago

Media Write Error (84)

I am playing with Accelerator on a 7.6.0.1 Master Server. I am backing up one server at this time with accelerator and I am going to a DataDomain. When I enabled Accelerator I noticed a difference in backup times, but still not seeing the complete benifit of Accelerator with the following information and errors.

 

not using change journal data for <F:\>: hard link or reparse point change detected 

not using change journal data for enumeration for <F:\> but will use it for change detection

I enabled "Use Change Journal" under the client settings and recieved the same messages. Each time though I did get a successful backup. It was when I enabled the Accelerator Force Re-Scan I started  having problems.

I began at that point to getting "Media Write Error (84)"

Removed the "Accelerator Force Re-Scan" and the 84 error went away, but backups are still not looking at the Change Journal on the Client.

 

Any help would be greatful.

7.6
Backup and Recovery
Configuring
NetBackup
Tip-How to
Windows Server (2003-2008)
  • Mark_Solutions's avatar
    Mark_Solutions
    11 years ago

    Something sounds really wrong - if all you did was to add the diff schedule it makes no sense why your earlier backups with a retention of 1 month have dissapeared

    You wont get rid of the Journal message as accelerator always checks to see if it can use it - but in view of what has gone on i would be inclined to create a new policy from scratch (do not copy the existing one) with all of the streams defined and you daily / weekly/ monthly schedules and run that one (disabling the other one)

    The first time it runs it will create a new track log (as it is based on policy name) and run a "real" full backup.

    The next full runs will use accelerator and incrementals will refer to the track log to assist them

    See if that sorts it out for you as it sounds like something is really wrong somewhere

    The only other thing i can think is that someone has expired some of the backups so removing the missing streams and causing accelerator not to work - but if you only actually see 2 jobs that that could not be the case either

    Try the new policy and see how that goes over a week or two

12 Replies

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  • Mark_Solutions's avatar
    Mark_Solutions
    Level 6
    11 years ago

    The backup will not use the change journal if you do have hard links or reparse points on the client - the journal itself cannot track them and notes it - so when NetBackup queries it it is informed of that and declines to use it.

    So it sounds like you cannot use the journal on that client (at least not always) : http://www.symantec.com/business/support/index?page=content&pmv=print&viewlocale=&id=HOWTO68492

    As for the 84 error i doubt that is connected  - just an issue when it does the full backup.

    We would need more info about the job, when and where it fails and some logs - at least bkkar / bpbmr to start with

     

  • billy_no_mates's avatar
    billy_no_mates
    Level 3
    11 years ago

    Greets OnRappell,

    I would second the 84 errors as being a coincedence, however with 7.6 being released recently I would also recommend having a look at logs on the Data Domain (determine your DDOS version and see compatibility matrix) and replicate errors again then dive into the ddfs.info file on the data domain:

    http://www.symantec.com/business/support/index?page=content&id=HOWTO59308

    General 'consultancy' thing:

    Accelerator is a great tool, however you need to understand the rate of change of your data on the client and determine whether its going to be useful for you; have a good look in the admin guide to ensure you're comfortable with using and understanding it, and how you're deploying your DD too. I never saw the need to use it and accelerator.

    Errors:

    Any errors in the Windows event manager?

    I'm assuming (although I'm not really assuming) no other 84 errors are being seen writing to the DD from other hosts? Have you used it in anger with/without accelerator and multiple-hosts?

    Lastly, http://www.symantec.com/business/support/index?page=content&id=TECH43243 - a good troubleshooting guide for 84's if you like good bedtime reading.

    Good luck,

    Billy. 

     

  • OnRappell's avatar
    OnRappell
    Level 3
    11 years ago

    It is weird that it happened only with the Re-scan option turned on. I did turn it off and was able to get successful backups.

    Now when it comes to using Accelerator how is it affected by Multiple Streams? The server I am using for test has a parent job and then 4 child jobs: C:\, D:\, F:\, and Shadow Copy Components. First backup using Accelerator had all five jobs running. Now that it has been running a few days, all I see is Shadow Copy Components and D:\. When I go into the Backup, Restore application I only have those two drives available for restore. Does this mean that there was nothing changed for the NBU to backup and the only changes took place on those two entries?

     

  • Mark_Solutions's avatar
    Mark_Solutions
    Level 6
    11 years ago

    Very strange that you only see two jobs running - it really should have all of the streams submitted as jobs and run, even if they back nothing up

    But if you only see 2 directories in the BAR GUI it implies that you have no backups for the others!

    What are you retention periods set to - just wondering if something has gone amiss somewhere

    Otherwise the policy or track log may have become corrupted in some way

    Let us know your retentions first just in case that is the issue.

    Hve you changed the policy at all since you created it?

  • OnRappell's avatar
    OnRappell
    Level 3
    11 years ago

    Retention Period is for 1month on  Diffs and Full. 1 Year for monthly.

    I added Diffs after I had created the policy.

  • Mark_Solutions's avatar
    Mark_Solutions
    Level 6
    11 years ago

    Something sounds really wrong - if all you did was to add the diff schedule it makes no sense why your earlier backups with a retention of 1 month have dissapeared

    You wont get rid of the Journal message as accelerator always checks to see if it can use it - but in view of what has gone on i would be inclined to create a new policy from scratch (do not copy the existing one) with all of the streams defined and you daily / weekly/ monthly schedules and run that one (disabling the other one)

    The first time it runs it will create a new track log (as it is based on policy name) and run a "real" full backup.

    The next full runs will use accelerator and incrementals will refer to the track log to assist them

    See if that sorts it out for you as it sounds like something is really wrong somewhere

    The only other thing i can think is that someone has expired some of the backups so removing the missing streams and causing accelerator not to work - but if you only actually see 2 jobs that that could not be the case either

    Try the new policy and see how that goes over a week or two

  • billy_no_mates's avatar
    billy_no_mates
    Level 3
    11 years ago

    "First backup using Accelerator had all five jobs running. Now that it has been running a few days, all I see is Shadow Copy Components and D:\."

    --> If they data was backed up it would be there for recovery unless it has expired :) Did you verify you could see/restore the data in BAR for the 1st backup?

    Back to basics: Ensure that this client is able to backup all the drives + Shadow Components without Accelerator in a standard policy with suitable retention levels to storage. Verify you can browse from BAR.

    My next thought is how you've got your DD configured and what DDOS you're using? Is OST configured here? If so, revisit support for plugins and versions with Accelerator support. Verify with HCL and let us know how storage is configured.

    Mappings files: not a bad idea verifying even though you're running 7.6.0.1 so arguably you have the latest: https://sort.symantec.com/checklist/install/nbu_device_mapping

    Are the track logs created on the client? No space issues? *giggle* Check out (carefully) installationdir/NetBackup/Track/ and determine what directories are created (should reveal the volumes backed-up according to policy)

    The original 84 errors: Please review ddfs.info log on the DD and as Mark asked: bpbrm (media) bpbkar (client) logs.

    - Billy

  • OnRappell's avatar
    OnRappell
    Level 3
    11 years ago

    I will be working through the suggestions today guys. Thanks a lot for all the help.

  • provnb's avatar
    provnb
    Level 2
    11 years ago

    Hi,

    I encounter the same problems. It seems the track_journal is corrupt. After deleting backup works fine. But I don't know what caused this.

     

    - ruud