Data center move - VM replication?

[REALM]

I'm not an expert level VMWare Admin so need some help.

I have 3 ESX hosts, with the VM's all stored on a Hitachi 9570 SAN.

We're moving everything downstairs. I have a 2nd SAN (HP) available.

How and what products can I use to replicate to the 2nd SAN as if it was a DR SAN? My goal is to have active replication (i.e. it continually updates the 2nd SAN with the latest VM files), and when I turn my Hitachi SAN off for the move, the others take over.

Thank you.

[Rodos]

A couple of quick questions which will help people answer.

How many VM's? How much used data (rather than total space on SAN)? How long is your outage window for the cutover? Can the systems be down for 30m, 1h or more? Lastly can it be assumed this is a temporary solution for your migration or is it something you want ongoing for DR?

[REALM]

Our outage for the move is 24 hours, so the systems can be down that long, including the move... which is a SAN unit and rack of ESX servers moving 1 floor down.

A total of about 30 VM's, taking up probably 10-20GB or so on average (actual data).

Correct, this would be only for the temporary move.

My worst case is just present space from SAN #2 to the ESX boxes, shutdown all the VM's, clone them over to SAN #2, move the boxes and SAN#2, reconnect everything, and startup the original VM's that are on SAN #1.

However, management is wanting a better solution if possible, one that doesn't require me taking time to clone the VM's in an outage, but where they would replicate during the work week to SAN #2, so that when the weekend move comes we can just shut everything down and move it.

[Rodos · Accepted solution]

Okay its getting a little clearer. Is your goal to migrate to the HP SAN or to stay on the Hitachi? From what I understand you want to migrate SANs during the move but keep your server hardware.

You only have a small amount of data. You are going to have to turn off and do a final incremental update of the data at migration time away. Is doing the full copy going to be that much longer in time than an incremental update? You have do 24 hours.

Do you need to clone the machines? Can't you just move the VMs from one datastore to another? Have you done a test move and timed the performance?

Don't forget to add time in to do a backup of you data first!

As a thought. Before the move

1. Connect SAN2 to current infrastructure.

2. Test move of a test VM to the SAN2 from SAN1 to estimate your migration times.

At move time

1. Backup data

2. Move VMs from SAN1 datastores to SAN1 datastores

3. Shutdown and move servers

4. Bring up servers and test

If you wanted to to keep a copy of the VM's on SAN1 you could but there would be a few extra steps.