Forum Discussion

Nicolas_Horchow's avatar
11 years ago

Netbackup : MSDP replication between remote sites within the same domain

Hello,

I'm looking for feedback about replicating data from MSDP media server on remote sites back to main site.

As they are on the same domain, I guess I won't be able to use AIR. Is there something similar for intra domain replication ?

Is there a way to boost finger print seeding ? (without using tapes or moving servers)

Or will it be better to create a local master server and use AIR ?

BTW, what is occuring if a regular duplication or AIR is failling ? Is there a resuming feature, or do we just rely on the learned deduplication info to partly recover the already duplicated info ?

Last be not least, I'm using resilient connection (works really nice with file backups). Is it possible to strip the stream to multiple streams ? I've got huge latency, and tcp is shapped.

Thanks for your feedback,

  • Hi Nicolas,

    Please find the answers inline.

    As they are on the same domain, I guess I won't be able to use AIR. Is there something similar for intra domain replication ?

    AIR is about replication between two master server, Duplication is for multiple media server under one master server. Both of them used same optimized duplication process.

     

    Or will it be better to create a local master server and use AIR ?

    If possible, Master server will be good on remote site.

     

    Is there a way to boost finger print seeding ? (without using tapes or moving servers) --

    Refer to this technote

    http://www.symantec.com/business/support/index?page=content&id=TECH144437

     

     I'm using resilient connection (works really nice with file backups). Is it possible to strip the stream to multiple streams ? 

    Resiliency is per socket connection hence you can have multiple data streams from client to media server.

    BTW, what is occuring if a regular duplication or AIR is failling ? Is there a resuming feature, or do we just rely on the learned deduplication info to partly recover the already duplicated info ?

    Duplication/Replication is similar to backup process - all or nothing, so if duplciation fails entire data related to it is deleted. Good thing is, SLP will keep on triggering duplication / replication till that copy is created hence there is no need to worry about - if copy will be created or not.

  • MSDP -> MSDP optimised duplication in the same domain is no different from AIR replication. If you cannot move the server for first duplication, it will take a long time. From there on only changes will be duplicated.

    HOWTO doc can be found here  http://www.symantec.com/docs/HOWTO36345  

    See links at the bottom of this page for additional HOWTO's.
    These docs also explains how failures are handled and retried.

    Read up on MIN_GB_SIZE_PER_DUPLICATION_JOB and MAX_GB_SIZE_PER_DUPLICATION_JOB in the LIFECYCLE_PARAMETERS file to accomplish the equivalent of multiple duplication streams.

    See NetBackup 7.5 Best Practice - Using Storage Lifecycle Policies http://http://symantec.com/docs/HOWTO73205

    Hope this helps.

  • Hi Nicolas,

    Please find the answers inline.

    As they are on the same domain, I guess I won't be able to use AIR. Is there something similar for intra domain replication ?

    AIR is about replication between two master server, Duplication is for multiple media server under one master server. Both of them used same optimized duplication process.

     

    Or will it be better to create a local master server and use AIR ?

    If possible, Master server will be good on remote site.

     

    Is there a way to boost finger print seeding ? (without using tapes or moving servers) --

    Refer to this technote

    http://www.symantec.com/business/support/index?page=content&id=TECH144437

     

     I'm using resilient connection (works really nice with file backups). Is it possible to strip the stream to multiple streams ? 

    Resiliency is per socket connection hence you can have multiple data streams from client to media server.

    BTW, what is occuring if a regular duplication or AIR is failling ? Is there a resuming feature, or do we just rely on the learned deduplication info to partly recover the already duplicated info ?

    Duplication/Replication is similar to backup process - all or nothing, so if duplciation fails entire data related to it is deleted. Good thing is, SLP will keep on triggering duplication / replication till that copy is created hence there is no need to worry about - if copy will be created or not.

  • Many thanks for your answers.

    I'm not using yet SLP on Netbackup 7.5 (poor implementation, I prefer using vault jobs). But SLP in 7.6 seems to be perfect (specific replication window and better backlog management).

    Just one last thing, about failing image replications is the fingerprints lost ?

    I've found that during a regular backup, it looks like the already transfered fingerprints were kept (client side deduplication).

     

    BTW, Marianne, is MAX_GB_SIZE_PER_DUPLICATION_JOB valid for MSDP to MSDP jobs, or is it for tapes only ?

     

  • Those are SLP parameters for all duplications.

    Not too sure about fingerprints for failed duplications. They may be kept because of the default three attempts.

  • Thanks Marianne.

    I've started my tests, I should have results quickly :)

    (I hope that 7.6 will be fully released soon too)