Monday, January 26, 2015

DELL 13G servers with PERC H730 finally certified for VSAN

I'm reading and learning about VMware's VSAN a lot. I really believe there will be lot of use cases in the future for software defined distributed storage. However I don't see VSAN momentum right now because of several factors. Three most obvious factors are mentioned below:

  • Maturity
  • TCO
  • Single point of support - if you compare it to traditional SAN based storage vendors support

That's the reason I didn't have a chance and time to play with VMware VSAN so far but I'm getting lot of questions from colleagues, DELL partners, customers and folks from VMware community about the right DELL storage controller for VSAN which can be used on the latest DELL server generation.

DELL 13th server generation was unveiled September 8, 2014. Since then, there was not any DELL storage controller for DELL 13G servers officially supported by VMware for VSAN.
Today I have got information that DELL PERC H730 is officially supported by DELL and VMware for VSAN. For more information look here.
This is really great info for VSAN early adapters planning to use DELL servers. One little advice to all VSAN enthusiasts ... If you are not going to use officially supported VSAN nodes or EVO:Rail appliance and you are designing your own VSAN cluster do it very carefully and don't forget to do PoC before or during design phase and perform design and operational validation tests (aka test plan) before putting VSAN into real production. Be sure you know something about queue depth of adapters (AQLEN) and disks (DQLEN).

If you build your own software defined storage then you are the storage architect with little bit higher risk and responsibility in comparison to classic storage system (this is my opinion). That's the risk of any modern (aka emerging) technology before it's become the commodity. On the other hand, this can be your added value to your customers and there are no doubts there are some benefits.

But never forget why "data centers" are so important and business critical? Because usually we have there very valuable data which must be always available with reasonable performance. Think about 99.999% storage up time with some reasonable response time (3-20ms) for expected IOPS workload.

I wish everybody lot of success with hyper converge systems like VSAN and leave a comment of your hopefully success stories and use cases. And I'm still looking forward for my first VSAN project  :-) 

4 comments:

Madness Gabrill said...

Verification and validation techniques applied throughout the development process enable you to find errors before they can derail your project.
they are involved in lot of process improvements which will actually help the clients to deliver best software.

software validation

David Pasek said...

Madness, thanks for your comment.

I absolutely agree with you that validation and verification should be done through the all development process and finalized with verification after implementation.

Ideally, validation and verification should start with particular technology workshops and Proof of Concepts before design phase. We can call it workshop phase.

After workshop phase there should be assessment phase or feasibility study which can asses not only technical aspects but also financial and operational aspects of planned design.

In the plan & design phase it is expected from the Architect to do some theoretical verification and validations. That's the project phase where the Architect should prepare architectural design document and operational test plan together. Good verification plan should have defined success criteria with some expected results based on theory and experience.

In reality, each infrastructure project is actually system integration with specific requirements and constraints. Therefore you should always verify design goals with real system behavior after implementation.

Bugs and troubles can be in logical design, implementation, software-hardware-firmware combination, etc. and it is better to find bugs and potential errors before the system is placed in to production.

That's my point of view based on 20 years in IT industry and it helped me a lot in the past.

Jasben Bolt said...

I really like examining and also following ones write-up when i locate them incredibly beneficial and also fascinating.
That write-up is usually just as beneficial along with fascinating.Verification and Validation both are independent type of testing. Obviously,
If we look both of these activities as a whole, we can also call it testing.


software validation

David Pasek said...

Thanks Jasben for your comment.

I would say that Software industry is more accurate in testing terminology because software development is significantly more complex then infrastructure design. Software methodologies including testing into whole development cycle.

Very good article about validation and verification difference is here http://www.easterbrook.ca/steve/2010/11/the-difference-between-verification-and-validation/

I think that x86 Hardware Infrastructure Architecture is much younger discipline then software architecture :-) Therefore terminology is sometimes mixed. However I feel that modern infrastructure architects are leveraging software architecture concepts.

Based on very good definitions in the referenced article I would say that during infrastructure design we usually prepare validation tests to be sure we fit all customers requirements. Let's call it Design Validation Test Plan. We should also prepare Operational Validation Test Plan to be sure operators are able to manage implemented system because it is obvious requirement for any system. And at the end of the project I also do System Health-Check Verification to be sure that system is implemented in good quality and in compliance with design documentation and industry best practices for things not documented in design. Final system implementation quality always depends on quality of implementer.

Does'it make sense?