We are transitioning datacenters and looking for optimal data migration techniques. Our current filers are Ontap 8.2 7-mode and we will be moving to new filers at Ontap 8.2 Cluster mode. With this configuration snapmirror is not an option as it does not work from 7-mode to cluster mode filers. We have about 40 TB of data to move, in which half is for a vSphere environment and the other half are direct attached storage to physical servers. The physical servers are a mix of UNIX and Windows and the protocol is mostly iSCSI, but we do have a few NFS volumes as well. We plan to migrate the vSphere storage using Storage vMotion technologies. Our current struggle is to find the best way to migrate our iSCSI data on the physical servers. We ran across the NetApp DTA2800 device as a possible solution, but there seem to be a lot of set backs. It seems that the DTA2800 only supports offline migrations for iSCSI luns. Does anyone know typical migration speeds of the DTA2800 for iSCSI migrations? Also, our new filers and old filers are in separate physical locations. Does the DTA2800 device support migrations between datacenters? What other options might we have to migrate our iSCSI data, online and at an optimal transfer speed?
Back when I was looking at cluster-mode (a year ago?), snapmirror between 7-mode and Cluster-mode WAS supported, but only as a PS engagement for data migration - you might want to ask your NetApp rep.
That being said, for your iSCSI data, if you've set your unix boxes up with LVM, you can present luns from the C-mode system to the hosts and do a host side mirror to migrate the data, which is online except for boot luns. I'm not sure if Windows offers the same functionality. For your NFS data, you can present a new share from C-mode, rsync (or robocopy, etc.) the data over to the new share - though there is some downtime there for the flip.
I'm curious though - I'm assuming your hosts are part of the datacenter transition as well. How are you going to move them without downtime?
We do have a NetApp engagement team who made us aware that snapmirror is not possible from 7-mode to Cluster mode. Maybe this is new with Ontap 8.2?
We have discussed using LVM for our linux servers, but this is a small portion of our overall data. For the NFS data we are discussing using the NetApp Transition tool which will allow us to perform online mirrors to the new storage and we will be able to perform the cutover during a maintenance window. Performing live migrations of the Windows iSCSI data is still our primary concern. We'd like to do some type of mirror ahead of time and be able to do a simple cutover during a monthly maintenance.
Are you referring to our ESXi hosts? We are not migrating our hosts. Currently we have HP blades but we are moving to a Cisco UCS flexpod solution. So, we can use vSphere technologies to move the VM storage live, and cut over hosts during a short maintenance window. If you are referring to our physical standalone servers, we do plan to move those during maintenance. The datacenters are physically located just blocks from eachother, so this move can be done in one night.
Interesting - it looks like the transition tool is new in 8.2, but it looks like it uses snapmirror under the covers, based on the requirement for a snapmirror license.
I was asking about the direct-connected hosts, not the ESX hosts. It sounded like you were wanting to do the entire migration with no downtime, and I was curious how you were going to handle the hosts - but you say you can take a downtime for that migration. I understand now!
I don't know anything about the DTA. I saw something that said it was online or offline, but it also said from non-NetApp storage to NetApp. It sounds like you need to do host-side migrations on the Windows iSCSI data, which I can't help with. I wonder if you can get a definitive "you can't use snapmirror to migrate this data, period" from NetApp, or if you keep pestering them they'll reveal that you can.
Maybe you might want to take a look at www.vicom.com ? It's a paid solution, but they can migrate data between SANS at about 1tb an hour without downtime and they do all of this at block level. We used their services to migrate from a Hitachi USPV to Netapp which was very successful. But the SANs were in the same datacenter. Hope this helps.