topic Re-synching Filers after a site failover scenario in ONTAP Discussions https://community.netapp.com/t5/ONTAP-Discussions/Re-synching-Filers-after-a-site-failover-scenario/m-p/53420#M12475 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P></P><P>One of our customers has asked about re-synching Filers after a site failover scenario. Is it correct that if site A has failed over to site B, eg link dead, and site B is made read/write, and promoted to primary for a period of time, once the link is re-established, do we need to do a full baseline copy of all the data from site B back to site A? Or just the deltas that have been written to B during the outage period?</P><P></P><P>I did think that as long as both sites have the same last snapmirror snapshot present, it would just require a snapmirror update and site B to send back the deltas/snapshots taken during the outage period? But if the last snapmirror snapshot has been deleted from site B, or overwritten, depending how long the outage was for, would that require a full baseline copy back to A (maybe using an NDMP tape to ship back to A and re-seed locally??)</P><P></P><P>If you could shed some light on this, that would be much appreciated!</P><P></P><P>Regards,</P></BODY></HTML> Thu, 05 Jun 2025 07:00:19 GMT biescas 2025-06-05T07:00:19Z Re-synching Filers after a site failover scenario https://community.netapp.com/t5/ONTAP-Discussions/Re-synching-Filers-after-a-site-failover-scenario/m-p/53420#M12475 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P></P><P></P><P>One of our customers has asked about re-synching Filers after a site failover scenario. Is it correct that if site A has failed over to site B, eg link dead, and site B is made read/write, and promoted to primary for a period of time, once the link is re-established, do we need to do a full baseline copy of all the data from site B back to site A? Or just the deltas that have been written to B during the outage period?</P><P></P><P>I did think that as long as both sites have the same last snapmirror snapshot present, it would just require a snapmirror update and site B to send back the deltas/snapshots taken during the outage period? But if the last snapmirror snapshot has been deleted from site B, or overwritten, depending how long the outage was for, would that require a full baseline copy back to A (maybe using an NDMP tape to ship back to A and re-seed locally??)</P><P></P><P>If you could shed some light on this, that would be much appreciated!</P><P></P><P>Regards,</P></BODY></HTML> Thu, 05 Jun 2025 07:00:19 GMT https://community.netapp.com/t5/ONTAP-Discussions/Re-synching-Filers-after-a-site-failover-scenario/m-p/53420#M12475 biescas 2025-06-05T07:00:19Z Re: Re-synching Filers after a site failover scenario https://community.netapp.com/t5/ONTAP-Discussions/Re-synching-Filers-after-a-site-failover-scenario/m-p/53425#M12476 <HTML><HEAD></HEAD><BODY><P>You are correct.&nbsp; As long as you have a common snapshot between the 2 volumes then you can "snapmirror resync" back to production.&nbsp; Without a common snapshot you need to re-baseline.&nbsp; If you are going to seed with tape, use snapmirror to tape.</P></BODY></HTML> Fri, 11 Feb 2011 17:50:24 GMT https://community.netapp.com/t5/ONTAP-Discussions/Re-synching-Filers-after-a-site-failover-scenario/m-p/53425#M12476 scottgelb 2011-02-11T17:50:24Z