Question

Re-Copy bad chunks on secondary copy

  • 8 August 2023
  • 3 replies
  • 166 views

Badge +1

Here is the situation: 

Primary copy - main site

Secondary Copy - DR site 

Tape Copy - DR Site

 

We are doing Aux copy from Primary > Secondary and Secondary > Tape

We got alot of errors reading chunks when doing Aux to Tape. we noticed that those jobs fail to restore from Secondary copy also , on Primary site , jobs can restore

 

Can i mark chunks/jobs as bad on secondary copy and have commvault recopy the jobs INCLUDING the bad chunks from Primary copy again and not save bad chunks due to dedup ?


3 replies

Userlevel 7
Badge +23

Hi @Tomer A,

You should use a DDB verify operation (with option #2) to find and mark the bad blocks as bad, and then you can initiate a recopy operation. You want to do this as future auxcopies are likely to be unrestorable if they reference bad blocks - its not good enough to simply re-copy a job alone as it assumes the blocks are good and does not replace them.
 

If you suspect there are bad blocks on the primary copy you should verify that first

 

Badge +1

if i mark job as bad on all copies will it mark its unique blocks bad also for future jobs?

Userlevel 7
Badge +23

if i mark job as bad on all copies will it mark its unique blocks bad also for future jobs?

Unfortunately that wont do it - all it does is prevent it from being copied - besides, there might be other jobs relying on one or more of the blocks associated with this job that are good - you don't want to mark those bad. The best way is the one I mentioned, its exhaustive but it literally checks each block to make sure its good, and if not, it immediately stops de-duplicating against it to protect future jobs.

 

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