ESXi and NAS Replication

[adcorbett]

I am currently testing a setup. I have 2 ESXi servers, and 2 Iomega StorCenter ix4-200d's (shared storage). I have one ESXi server as a backup on one running live. All the VMs are on one of the Iomega shared storage devices. What I am trying to do is to have the 2nd shared storage unit as a failover for the first. My problem is replication. How can I mirror only the changes to VMs without having to copy the entire VM each time? Each VM is about 40Gig and there are are 5 of them, so replication takes a long time right now. Is there any way to keep the VM's mirrored as close to real time as possible between the 2 shared storage devices?

[a2alpha]

Vizioncore vReplicator or Veeam Backup and Replication should do it as it only copies the changes after the initial pass. The more frequent you do the replication the less changes you need to replicate each time and the faster it would be. Need to be careful about which version of ESXi you use as the free one doesn't allow ssh which is what they use. Its worth looking at though.

[Gostev]

adcorbett, are you using ESX4?

[bulletprooffool]

Does you NAS have any block level replication built in?

the best solution is usually to use the tools provided by the vendor for the hardware you are using.(if they exist)

[Gostev]

Well, this is definitely NOT the best solution, because storage block-level replication provides crash-consistent replicas (not properly queisced). Powering on such replica may cause lost application transactions and corrupted storages.

[adcorbett]

Yes, I am using ESXi 4.0

[Gostev]

I am asking because VMware did some truly awesome job with ESX4, and we as a vendor are fully leveraging its new capabilities to achieve very fast replication cycles...

You should definitely check out our upcoming version of Veeam Backup 4.0 when it becomes generally available (in the coming weeks). We have a number of very exciting replication enhancements there, particularly what we call "near-CDP replication"... What would you say if I tell you that based on the closed beta feedback, incremental image-level replication cycle for 20GB VM takes under 1 minute?

If I got you interested, more info on this new release (incl. video) can be found here:

One thing I must note right away however (in order to properly set your expectations), is that ESXi is currently only supported as source host, while target host must be full-blown ESX for replication. However, we will be adding support for ESXi as replication target in the near future.

[rengler]

To answer the original question, I don't think the 200d's will serve as you'd like. You will need to layer another application on top somehow to get the bits moved correctly.

How do you like the 200d's otherwise? I'm getting some soon and I'm worried that they won't have enough horsepower to keep up with several VMs.

-Rob