ONTAP Discussions

About Snapmirror cascade


Hi, Everyone


Thank you for your reply last time.

I'm considering the migration separately from the design, so I asked the question.

This time, we are considering data migration using Snapmirror.
The current configuration is below.


A. Production storage (current)
Ontap: 9.5P6
Usage for migration: FileServer (CIFS/NFS), ProfileServer (CIFS, NFS)


B. Backup storage (current)
Ontap: 9.5P6


C. New production storage
Ontap 9.11P3


Now from A to B,
Snapmirror is implemented.

In order to avoid the current business impact as much as possible, data migration to the new production storage
We are considering migrating from B to C using Snapmirror.
(It's a Snapmirror cascade.)


I am considering implementing the following flow, but is it correct?
Are there any other points to note?


1. Backup storage (current) Ontap version upgrade (9.5 → 9.7)
We expect to update to a version that supports Snapmirror to 9.11.
Since it is an OEM product and the minimum version that can be downloaded from the support site is 9.7, this version is used.


2. Snapmirror implementation from B to C
Create and implement a peer relationship between the cluster and svm. Assuming XDP.


Since various operations are performed only on B and C, it is assumed that there will be no operation or impact on A.
After version upgrade of B, SnapMIrror from Ontap:9.5(A) to Ontap:9.7(B) is also supported configuration.






Hi there,


I'm sorry this has gone a week without an answer. I have concerns about your design, but more information is needed


1. Are they currently using snapmirror synchronous from A to B?

2. Are all relationships XDP? or some DP?

3. What is the desired end-state? What hardware will be in operation, what will be primary?


Thank you for your reply. I will answer below.


1. I am not using SnapMirror synchronous. All will be Async MIrror.
2. All will be XDP.
3.AFF250(C) will be the Primary storage. I didn't write it down,FAS2720 is present for new backup storage (D).
However, there is no need to back up the data migrated from B to C with Snapmirror.
Snapmirror to D is not required.



In order to create a compatiblie SnapMirror DR relationships for policy type 'async-mirror"

You have to downgrade the 'C' (New production storage - AFF A250) from version 9.11P3 to 9.10.1.

Also, you have to upgrade the 'A' (Exisiting Production Storage - FAS8020) to 9.8.

If you want to continue the current replication from A -> B, you should have to upgrade the 'B' (Backup Storage - FAS2554) in the first step and then move forward with upgrading 'A' to plan a consistent data migration.


Thank you for your response.

The customer requests the following.

・The customer does not want to operate (Upgrade) on production storage A (FAS8020).  And there is no problem with the current operation (Snapmirror from A to B).
・Downgrading of the new production storage C (AFF250) is not performed.

In this case, which version of the current backup storage B is appropriate?
The version does not have to be 9.7, we would like to know the appropriate version.

Or would an Ontap Upgrade of production storage A be mandatory?