Would you ever use a service company other than the OEM to perform hardware and software maintenance in your datacenter? Specifically on: Cisco, Dell, EMC, HP, IBM, and SUN
1. Yes - I would and why?
2. No - I would not and why?
It will be very helpful for me if you can please expand as much as possible on either one.
I would be comfortable having a third party with a good reputation service my out-of-warranty hardware -- in fact, I have done that quite often. Understanding terms of service is key. For example, "response time" can be tied to a return phone call or an actual site visit, so find out if the service contract details will meet your expectations. Check out service windows, parts availability, escalation procedures, penalties for SLA non-compliance, your responsibilities, exit strategies, etc.
I'm not familiar with software service, so maybe somebody else can help there.
Basically, I believe that the OEM, being the people who supplied me the hardware in the first place, should be in the best position to keep the hardware running in good order even after the warranty has expired. This is especially so if we are talking about brand-name equipment like those you mentioned. Being an existing customer, I should be eligible for special discounts on spare parts and upgrades. Third party support must necessarily be cheaper to compete but we are talking about a data center and not a desktop pc. So saving a few dollars would be a very costly gamble in the long run.
With regards to software, if it is not open source then it must be licenced. I cannot imagine a data center running on pirated software. So being licenced software it must come bundled with support. Said support must be paid for and upgrades are part of the deal. Myself, I always go for open source, not just because it is free, but mainly because it is better. In the case of open source software, upgrades are always accessible as soon as they are available. Don't tell me that open source software have bugs. When you pay for licenced software, the developers throw in the bugs for free. And there is no way for you to look in the code to see where the bugs are lurking. With open source software, the code is there in plain sight, assuming you can read code.