Forum Discussion

Taqadus_Rehman's avatar
14 years ago

Sync Replication Queries

Hi,

I have installed VVR for synchronus replication. I am replicating SQL data from primary to secondary site (no sql agent installed). I have tested the replication by doing some changes in SQL database and migrating the primary/secondary role and changes are reflecting in files la ying at secondary site and vise versa.

1. my vxrling commaind showing data is up-to-date. when I place new data on primary RVG (like folders, files, etc.) vxrlink shows X outstaning writes and not  replicating these to secondary site. as soon as i stop the replication these folders/files are visible to me.

can anyone explain?

2. Is not VVR creating auto check points? we have to create a checkpoint and end it when we start/stop replication. 

3. Can we have multiple rlinks for single RDS.

 

Regards,

Taqadus

  • If replication is not paused then when you place new data on the primary, you may see X outstanding writes briefly, but then those writes should be written to seconday and replication should show "up-to-date" - unless you are continually writting.  You cannot "see" data on the secondary as it is readonly - you can assign a drive letter as a readonly drive, but as Windows it not expected a readonly drive to change it will not  show updates to the drive and this is not supported as anything you copy or view from the drive may look corrupted as data maybe changing underneath (however if you place new data on primary, then unassign drive letter at secondary and then reassign you will be able to see your new data).  If you stop (not pause) replication then both sites become writable and you can see data on the secondary if you assign volume at secondary a drive letter.  Similarly if you reverse replication, you will be able to see and access data on the secondary.

    Checkpoints are only required at certain times, like starting replication and are not used when replication is running normally.  Normally you would not "stop" replication, you only "pause" or reverse direction.

    You can have multiple rlinks meaning you can have multiple secondaries.

    Mike

     

  • If replication is not paused then when you place new data on the primary, you may see X outstanding writes briefly, but then those writes should be written to seconday and replication should show "up-to-date" - unless you are continually writting.  You cannot "see" data on the secondary as it is readonly - you can assign a drive letter as a readonly drive, but as Windows it not expected a readonly drive to change it will not  show updates to the drive and this is not supported as anything you copy or view from the drive may look corrupted as data maybe changing underneath (however if you place new data on primary, then unassign drive letter at secondary and then reassign you will be able to see your new data).  If you stop (not pause) replication then both sites become writable and you can see data on the secondary if you assign volume at secondary a drive letter.  Similarly if you reverse replication, you will be able to see and access data on the secondary.

    Checkpoints are only required at certain times, like starting replication and are not used when replication is running normally.  Normally you would not "stop" replication, you only "pause" or reverse direction.

    You can have multiple rlinks meaning you can have multiple secondaries.

    Mike

     

  • Hi Taqadus,

    VVR supports up to 32 secondaries in a replication set with each having its own pair of rlinks.

     

    To add to what Mike said, if you need to access the data on the secondary side to validate that it is good, then you should use snapshots at that site.

     

    Thanks,

    Wally