Dell EMC Unity: How To fail back without synchronization for FILE Replication (User Correctable)
Summary: You may run into an event where you had to failover Replication to a Disaster Recovery (DR) site, while failed over data was either corrupted or accidently deleted, and you do not want to failback to source side as it will replicate the bad data back. ...
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Instructions
*** THERE IS NO FAIL BACK WITHOUT SYNC OPTION IN UNITY FOR REPLICATION ***
While there is NO fail back option without sync for Unity we can perform a couple of solutions so that the bad/missing data does not replicate back.
OPTION 1:
DELETE REPLICATE SESSION (Will require to run new FULL replication Jobs)
*We are assuming that primary data has been failed over to the DR site, and that the DR site is now corrupted. We are looking to recover back to the Source site without failing back as that would sync the bad data *
1. On the Unity DR site you will want to delete the Replication Session for the replicated NAS server and its associated File System.
A. From the GUI Select "File" from the dashboard
B. Select the "File System" Tab (first tab)
C. Select the File System associated with the problematic NAS server, and enter the file system properites
D. Select the "Replication" Tab
E. Select the "Delete" Button (this will break the replication session between Source Unity and DR Unity)
*** You will receive a "Job Failed" alert. This Alert is a notification that the replication session was deleted ***
F. Repeat Same Process now for the NAS Server (File System replication session has to be removed first before removing NAS Server Replication session) Note you will receive a Job Failed alert as you did when deleting the File System
2. On the Source Unity Site you will perform the same steps for deleting the Replication Session for both the NAS Server and its associated File Systems.
3. Once the replication sessions have been deleted you can go back to the DR Unity and delete the NAS Server and its Associated File Systems (Note: You will need to delete the Associated File Systems first before deleting the NAS Server)
4. Once the DR site NAS server and File Systems are deleted you can re-create the Replication from the Source Side
OPTION 2:
RECOVER FROM SNAP SHOT
* We are assuming that SNAP's are in use and scheduled on both Source and DR Unity site's.
** In this scenario we are assuming that the Primary Unity was failed over to the DR site, and while failed over data corruption occurred.
*** In this scenario we are also assuming that after failing over to the DR site a snap shot was taken to reflect current data status prior to fail over.
1. On the DR Unity site select the File System which you will recover the snap from
2. In the File System's properties select the "Snapshots" tab
3. Select the Snapshot from which you want to recover from, and select the "More Actions" drop down menu
4. From the drop down menu select "restore". This will roll back the data on the file system to when the snap shot was taken
5. Once restored verify that the data is accessible and good. Once confirmed good you can safely failback Replication to the Primary Unity Site.
6. If the data is still bad, you can try another checkpoint, otherwise proceed with following instructions from Option 1 above.
* Depending on the snap shot, and the data change from the snap shot the re-synchronization should take much shorter time to complete than a FULL sync would have in the first scenario*
While there is NO fail back option without sync for Unity we can perform a couple of solutions so that the bad/missing data does not replicate back.
OPTION 1:
DELETE REPLICATE SESSION (Will require to run new FULL replication Jobs)
*We are assuming that primary data has been failed over to the DR site, and that the DR site is now corrupted. We are looking to recover back to the Source site without failing back as that would sync the bad data *
1. On the Unity DR site you will want to delete the Replication Session for the replicated NAS server and its associated File System.
A. From the GUI Select "File" from the dashboard
B. Select the "File System" Tab (first tab)
C. Select the File System associated with the problematic NAS server, and enter the file system properites
D. Select the "Replication" Tab
E. Select the "Delete" Button (this will break the replication session between Source Unity and DR Unity)
*** You will receive a "Job Failed" alert. This Alert is a notification that the replication session was deleted ***
F. Repeat Same Process now for the NAS Server (File System replication session has to be removed first before removing NAS Server Replication session) Note you will receive a Job Failed alert as you did when deleting the File System
2. On the Source Unity Site you will perform the same steps for deleting the Replication Session for both the NAS Server and its associated File Systems.
3. Once the replication sessions have been deleted you can go back to the DR Unity and delete the NAS Server and its Associated File Systems (Note: You will need to delete the Associated File Systems first before deleting the NAS Server)
4. Once the DR site NAS server and File Systems are deleted you can re-create the Replication from the Source Side
OPTION 2:
RECOVER FROM SNAP SHOT
* We are assuming that SNAP's are in use and scheduled on both Source and DR Unity site's.
** In this scenario we are assuming that the Primary Unity was failed over to the DR site, and while failed over data corruption occurred.
*** In this scenario we are also assuming that after failing over to the DR site a snap shot was taken to reflect current data status prior to fail over.
1. On the DR Unity site select the File System which you will recover the snap from
2. In the File System's properties select the "Snapshots" tab
3. Select the Snapshot from which you want to recover from, and select the "More Actions" drop down menu
4. From the drop down menu select "restore". This will roll back the data on the file system to when the snap shot was taken
5. Once restored verify that the data is accessible and good. Once confirmed good you can safely failback Replication to the Primary Unity Site.
6. If the data is still bad, you can try another checkpoint, otherwise proceed with following instructions from Option 1 above.
* Depending on the snap shot, and the data change from the snap shot the re-synchronization should take much shorter time to complete than a FULL sync would have in the first scenario*
Affected Products
Dell EMC Unity FamilyProducts
Dell EMC Unity FamilyArticle Properties
Article Number: 000019213
Article Type: How To
Last Modified: 24 Sep 2024
Version: 3
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