Monday, July 29, 2019

Nutanix Near Synchronous (Near-sync DR)


NearSync DR provides the best of both worlds (Sync and Async), zero impact to primary I/O latency (like async replication) in addition to a very low RPO (like sync replication (metro). This allows users have a very low RPO without having the overhead of requiring synchronous replication for writes.
By using NearSync DR feature the RPO would be (up to 1-minute RPO), you can set your schedule to 1 minute to 15 Minutes,

Before you start you need to make sure that your network connectivity between both sites is healthy and both sites are reachable from the other site,

From Main site Prism interface click on the main tab and go to Data Protection and click on it


Now we need configure each site (Main Site and DR Site) as the Remote Site to the other site, then configure Network and Storage Mapping, create protection domain, add which VM's will be protected,

Please check the following post: 
Async DR - Basic setup and Protection Domain Configuration for the required steps to configure Remote Site to the other site and configure Network and Storage Mapping,

Once all are ready and both sites are added as remote site to the other site then we need to create a protection domain which will contain our target VM's that will be protected, from Data Protection page, click on "+ Protection Domain" and then click on "Async DR"


Give the Protection domain a name and click on Create


Select the VM's and if any related Volume Groups you need to protect with your VM's from the list and then click on "Protect Selected Entities"


Your VM's now will be shown as a Protected Entities, Click Next ->


Now it is the time to set the Replication Schedule, Click on "New Schedule"


From Schedule menu on Configure your Local Schedule select "Repeat Every: 1 minute", 

If your remote Cluster is not meeting the minimum requirements you will get the following error message: "Error Saving schedule. High frequency schedule not allowed on Remote site"

If all good and all requirements configured correctly then you are good to GO!


For the Retention Policy it is actually diffrent than the normal Async, for the Local and to DR retention you have the option to set it to "Days" or "Weeks" or "Months",

In the following example i will set the retention to "5 Days" then the snapshot schedule will be the following:
  • Snapshot every one minute retained for 15 Minutes
  • Snapshot every one hour retained for 6 Hours,
  • Daily snapshot retained for 5 Days
In our example here if you changed the value from 5  to 10 then only the last retention will be changed from 5 Days to 10 Days however the first two retention will remain the same one minute retained for 15 Minutes and one hour retained for 6 Hours,




In the following example i will set the retention to "5 Weeks" then the snapshot schedule will be the following:
  • Snapshot every one minute retained for 15 Minutes
  • Snapshot every one hour retained for 6 Hours,
  • Daily snapshot retained for 7 Days
  • One Weekly snapshot retained for 5 Weeks
In our example here if you changed the value from 5  to 10 then only the last retention will be changed from 5 weeks to 10 weeks however the first three retention will remain the same one minute retained for 15 Minutes and one hour retained for 6 Hours and daily snapshot for last 7 Days


In the following example i will set the retention to "5 Months" then the snapshot schedule will be the following:
  • Snapshot every one minute retained for 15 Minutes
  • Snapshot every one hour retained for 6 Hours,
  • Daily snapshot retained for 7 Days
  • One Weekly snapshot retained for 4 Weeks
  • One Monthly snapshot retained for 5 Months
In our example here if you changed the value from 5  to 10 then only the last retention will be changed from 5 Months to 10 Months however the first four retention will remain the same one minute retained for 15 Minutes and one hour retained for 6 Hours and daily snapshot for last 7 Days and weekly snapshot for last 4 Weeks


Now we are done configuring our protection and replication will start sending the date from Main site to DR site, always remember that first time of the replication will take much time since it is a full copy of your data located in main site, after first time replication completed the new replication will be only the changes

As you can see below, a snapshot will be available for restore every 1 minute 



For recovery options please check the following posts covering diffrent recovery scenarios:














No comments:

Post a Comment