As you are most likely aware I was an attendee at the TechFieldDay event at Boston, and as is Steve’s wont we managed to get a presentation from a Stealth Start-up. Now we have been able to say the company name Zerto but not much else. However that is now about to change.
So what exactly is Zerto, well obviously they are a company 😀 but their technology is interesting, it virtualises the Storage stack to make it Array and Storage type agnostic,
The marketing video below explains it from30K ft.
OK I think I can here what you are thinking, Isn’t that a lot like what SRM does, well yes and no, to succinctly wrap up SRM, it utilises Array based replication techniques and scripting to manage a DR situation. Now the main part of that statement is “Array Based Replication”, the arrays at both sides have to be the same,
i.e. DMX at site A DMX at site B, you cannot have a VMX at site A, B, and C replicating to a DMX at site D
The technology that Zerto introduces allows that situation, now I can have my remote satellite sites utilising low end storage running on iSCIS or NFS or even DAS or even dare I say it FCoTR, to replicate to my centralised UBER array.
OK, so what about the “rumoured Host based replication” from VMware. Yes this does do what Zerto’s product does, however it is only for the next generation of ESXi, it will not manage vSphere components. We all know that vSphere environments will be here for a long time. The fact remains that there are still ESX 3.x Clusters out there, I would not be too surprised to learn of ESX 2.x.x environments either, although personally I have not come across one of those for a while. There will be a need for vSphere environments to remain in the Government/Federal space for quite a while yet, due to their requirement for higher security levels. vSphere has only recently been certified as EAL4+ complainant. That process took approximately 2 yrs to complete, and this was a fast tracked submission!
These people do and will have for a significant period of time have the requirement to provide resilience and redundancy in their Business Continuity and Disaster Recovery procedures. Currently they are forced into purchasing like arrays to allow replication to cover functionality like SRM.
Now I do not want to repeat what my fellow TechFieldDay delegates have put so below are a few links to read.
http://vninja.net – Ed Czerwin’s take on Zerto
http://www.vsamurai.com – Christopher Well’s take on Zerto
http://www.gabesvirtualworld.com – Gabes take on Zerto/
OK so lets take a closer look at the product, now before I dig deeper I have to say that as yet I have not as yet managed to gets hands on with the product. This is something I hope to rectify.
According to the presentation the architecture is based on a grid. This means that is should be scalable, of course that depends on the messaging infrastructure it utilises to carry update details. Each host needs a Zerto appliance to be running on it. These appliances look at the guests that are running on its host and manages their replication, if a guest migrates to another host the Zerto appliance seamlessly hands the management of that guest’s replication to the next host.
So what happens when a Guest moves?
As already stated the Zerto appliance seamlessly informs the receiving host’s Zerto appliance of the move and that then takes over the replication. Now to prevent a sudden burst of replication data, Zerto utilises VMware CBT to manage the differences, this means that after an initial replication burst to get the guest in the correct location only changed blocks are transmitted, further due to the Grid technology utilised in the management of the devices, each of the nodes in the Grid “knows” about all other nodes Guests.
So what happens when a Host Fails?
Well the first thing is that the Guests hopefully start up on another host 🙂 once this has occurred, the resident Zerto appliance notes the new machines and checks its local store of data to make sure that the machines replication status is up to date, and any changes are noted and copied across.
Now I am sorry that this is not a true deep dive on the technology, but as I said I have not as yet had the pleasure of playing with it. I must also say it will be interesting to see how the product stands up against VMware when the next rumoured version of ESX is releases with a very similar technology included.
I think that they have a good chance of making a reasonable amount of money and inroads, especially into places that due to certification requirements cannot be early adopters of the latest technologies.