Data Backup and Recovery

About XCP specifications for NFS

shirotan

Please tell me about the behavior of each command option.

<NFS>
copy:
I understand it as the initial synchronization of the source data.
Is it the behavior of scanning, listing files, and then copying?
Or is XCP doing the copy without SCAN?
(I understand that XCP stores the copied file information etc. in a separate catalog.)

 

sync:
I understand that by rescanning the source data and comparing it to the information stored in the catalog, I extract the delta data and copy the file.
Therefore, I understand that data copying can be started very quickly.
Since the comparison target is the information in the catalog, even if the destination data is changed, it cannot be recognized.
When migrating NFS data using XCP, the migration fails when the destination file is changed.
Is the above correct?

 

verify:
Verify does not use a catalog and needs to compare the source data with the data copied in sync.
Therefore, the behavior is such that the source and destination storage are SCANed, the list of files is compared, and the hash value of each file is also calculated and compared in order to confirm the actual data block of each file.
By the way, I understand that if you add the nodata option, the hash value of the file will not be calculated or compared.
Is it correct?

1 ACCEPTED SOLUTION

darb0505

Hi @shirotan ,

 

You are correct on the copy operation, it will scan, then copy the entire directory structure to the new destination location.  Regarding the sync operation, you are correct on the understanding.  XCP does not support live data on the destination side so it would fail the sync operation.  You are also correct when it comes to the verify operation.  It does a byte by byte comparison rather than using the catalog to compare anything.

 

Here are some documents that will help you answer some of your questions.

 

Links:

Hope this information helps.  Please let us know if you have any additional questions on XCP.  You can also reach out to NetApp Technical Support if you run into any issues with XCP.

 

Thanks,

Brad

 

Team NetApp

View solution in original post

1 REPLY 1

darb0505

Hi @shirotan ,

 

You are correct on the copy operation, it will scan, then copy the entire directory structure to the new destination location.  Regarding the sync operation, you are correct on the understanding.  XCP does not support live data on the destination side so it would fail the sync operation.  You are also correct when it comes to the verify operation.  It does a byte by byte comparison rather than using the catalog to compare anything.

 

Here are some documents that will help you answer some of your questions.

 

Links:

Hope this information helps.  Please let us know if you have any additional questions on XCP.  You can also reach out to NetApp Technical Support if you run into any issues with XCP.

 

Thanks,

Brad

 

Team NetApp
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