NetApp - Using SnapMirror to Migrate a 7mode NAS Volume to cDOT

At work, we're in the process of migrating from two FAS3250 running 7mode to two FAS8040's running clustered data on tap. Both sets of controllers are running side by side and we need to migrate everything from the 3250 to the 8040.

First hurdle, we have a bunch of ESXi hosts that boot from SAN.  Then we find out that it is impossible to SnapMirror SAN (FCP or iSCSI) volumes between 7mode and cDOT.  Had to rebuild all our ESXi hosts and do a full restore of our SQL cluster database since it was also on SAN volumes.

Next challenge, getting our many NFS volumes transferred over.  NetApp offers a transition tool to help with this process, but I did not try it. I found a bunch of guides on the NOW site and random blogs. They all missed a couple important steps which I wanted to document.

Here is the process I followed for migrating a 7mode NAS (nfs) volume to cDOT. DOES NOT WORK FOR SAN(fcp,iscsi) VOLUMES! I'm assuming the reader of this already has their cDOT system up and running with SVM's and LIFS configured.

CLUSTER = cDOT cluster name
NODE = individual controller node in the cDOT cluster
VSERVER = NAS SVM name
7MODE = 7mode controller with the source volume on it

Tab completion is your friend!

1. SSH into the cluster using your favorite SSH client. Sign in with admin account.
2. Set up a peer relationship
1. vserver peer transition create -local-vserver VSERVER -src-filer-name 7MODE
3. Create destination volume to snap mirror to
1. volume create -volume <volume name> -aggregate <aggrname> -size 100GB -type DP
4. Create an Intercluster LIF
1. network interface create -vserver NODE -lif intclust01 -role intercluster -home-node NODE -home-port <port that has connectivity to 7MODE> -address <ip address> -netmask <netmask>
2. network routing-groups route create -vserver NODE -routing-group <name> -destination 0.0.0.0/0 -gateway <gateway of the intercluster LIF IP>
5. Verify communication
1. network pint -lif intclust01 -lif-owner NODE -destination 7MODE
1. should say that it is alive.
6. IMPORTANT! This is where the other guides I found on the Internet failed.
7. On 7MODE, edit the /etc/snapmirror.allow file.
8. On a new line, put
1. interclusterLIF:<volume to SnapMirror>
2. example: fas8040-01:nfs_volume_01
3. The interclusterLIF name needs to resolve to the 7MODE system exactly how you type this name in here. I had to edit the /etc/hosts file on the 7MODE system and add an entry for my intercluster IP address to resolve to fas8040-01 before it would work for me
9. Back on the CLUSTER shell. Create the SnapMirror relationship
1. snapmirror create -source-path 7MODE:<src_volume> -destination-path VSERVER:<volume created in step 3> -type TDP
10. Initialize the SnapMirror
1. snapmirror initialize -destination-path VSERVER:<volume>
11. View progress
1. snapmirror show -destination-path VSERVER:<volume>
12. Status should be transferring. It took a few minutes for it to actually start transferring data for me.
13. If it is failed, log onto the 7MODE node and try to initialize the cluster again from the cDOT system. The 7MODE system might give you a clue as to what is wrong. Might have to go mess with /etc/snapmirror.allow or hosts.
14. The volume should now be SnapMirrored