Have a look at this article regarding how to get NX-OSv going in GNS3.
There is also an NX-OSv appliance available within Cisco's VIRL if you have access to that or wanted to go that route.
Also, depending on whether you're a customer or partner there are options on dcloud.cisco.com (sign in with CCOID). Partners have more access to labs but customers have some. Also look at DevNet for labs, although mostly focused on programming but gives you access to ACI and Nexus, among other things like UCS.
FYI, 7Ks aren't the focus of Cisco (9Ks are the future) so you may struggle to find hands-on in a lab with them. If looking for practice with OTV, you can spin up ISR VMs and they run the same technology, although some different syntax. INE has data center labs but not free.
oh and to answer your question about why...VMware is all software...there are a lot of functions on Nexus switches that are hardware-accelerated so can't mimic in software, therefore the only option is to have physical labs or limited VM options...hard to manage physical labs with a LOT of partners who would want access, let-alone customers.
One thing to note about the VM version, they are mostly meant to work with the control plane and get things like routing or VXLAN running but note you won't have data plane switching on them so not for full mimicking.
Hello friends, thanks for your help sorry for that time not replying now I am ready to go I have noe UCSPE and N9K VM run on top of VMW it consume 8Gig/Node I run only two of it I am going to focus on Cisco DC technologies as VMware Engineer I think it's better to give all my effort to vPC vDC FabricPath and ACI only from documents,CVDs and config guide that is enough I think any Suggestions
Hello vMoussa--FabricPath is no longer on the blueprint, so you can drop that topic from your exam studies.
vPC and ACI are definitely big topics in the exam. I would also recommend studying NX-OS, OTV, and storage (FC, FCoE and iSCSI). There's also UCS and virtual switching. Personally, I think the biggest challenge for the DC CCIE is the sheer volume of knowledge you have to command.
Studying from the available textbooks, white papers, and config guides will be a good start to prepping for the written exam, and you could pass the written without having a ton of access to the lab. But, after that, you have to bite the bullet and find a lab to prepare in.
Agree with Micheline_Murphy that you can ignore FabricPath, as most people are phasing this out and it's not sold net-new.
The below matrix I think is very helpful outlining config guides, books, and Cisco Live session to stream. This is the latest one with the new cert changes but CCIE DC v2.1 also has one specific to that exam. I highly recommend the deploying ACI book and a couple of the other ones like NX-OS and UCS are helpful. Also, I extensively have used the Cisco Live recorded sessions, highly recommend.
Also, note that if you're planning to take the CCIE after February, you will no longer be taking the written exam like before but need to instead pass the "Core" exam for DC, which is one of the requirements for the new CCNP DC.
Please look into this link for more details on the changes: CCIE Data Center Certification Program