Virtualization

Online survey of 110 VMware customers has surprising results

Memory overcommit has been a hot topic recently as it drives down the cost of using VMware over other vendors. An online survey was taken from 110 VMware customers. See the results.

Memory overcommit has been a hot topic recently as it drives down the cost of using VMware over other vendors. An online survey was taken from 110 VMware customers. See the results.

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I recently attended VMworld and wrote the following pieces: "VMware Says Memory Overcommitment Makes Them Cheaper than Both Microsoft and Xen Server" and "Microsoft Responds to VMware’s Ability to Overcommit Memory." After I wrote these posts, a colleague, John Troyer, pointed out an online survey that was conducted with 110 VMware customers.

Here are the results of the poll. After reviewing the poll, please continue reading to see my take.

VMware poll result

VMware poll result

VMware poll result

In the first poll, it is definitely apparent that memory overcommitment is being used. In the second poll, 87 percent of people are using memory overcommitment in both Test/Dev & Production. This number seems very high to me, and I have my doubts.

At VMworld during partner day, they took a hand poll of how many people were using memory overcommitment in production and very few people raised their hands. There were definitely more than 110 people in this room. Furthermore, do you believe this 110-person survey is a random sample of VMware users or was it handpicked?

I firmly believe that Microsoft intends to add memory overcommitment to its product line in the near future, but my big issue with memory overcommitment isn't what vendor has it or doesn't have it. My issue is that it is being used as a factor to buy a certain vendor's product. I do not agree with this tactic at all.

Memory Overcommitment has its place in test and development but should not be recommended for production systems. VMware doesn't even recommend it in their documentation. If you are a "newbie" in the VM space and you start messing with your memory in a production system, you are asking for trouble.

Please take my poll on how you feel about memory overcommitment.

If you are interested in reading this survey, please see "Memory Overcommit--Real Life Examples from VMware customers."

5 comments
mdhealy
mdhealy

Maybe some clever system builder could provide the best of both worlds by making a server with two classes of RAM, some high performance memory for ordinary use, and some cheaper low performance memory in case it runs out. Then configure the virtual machines so that all of them run in the fast RAM until it runs out, in which case some that are designated as lower priority get relegated to the slower memory.

Neon Samurai
Neon Samurai

In your server you want buffered ram built to higher quality for reliability. That buffering bit is a part of the jump in cost between unbuffered consumer and server ram. From recent reading, HP's servers can take extra ram sticks for redundancy. If the primary sticks fail, the server switches to the secondary and no one suffers an outage. I believe IBM also offers redundant ram through an add-in board. I can't remember if Dell also had the option for redundant ram in there rack servers or the range I looked at. All offer redundant cooling, power and RAID support for drives though.

Jaqui
Jaqui

you want the dev system to not have the increased possibility of a crash from excessive swap file / partition usage that overcommitting memory cuases. just like you want that stability on production systems, for the same reason, data corruption / loss prevention. on a test platform the overcommit can be used to push the app to the breaking point, so you can see what could happen to the dat and resolve the issue before it's critical.

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