HOST DEEP DIVE FIRST MAJOR MILESTONE
Exactly one month ago Niels and I published the VMware vSphere 6.5 Host Deep Dive and it is a major success. Within 30 days we sold over 4000 copies of the book. Building consistent high-performing ESXi hosts remains a strong focus point for the virtual community. The attention for the book is overwhelming. The hashtag #HostDeepDive felt like it was trending. Tweets from around the world letting us know the book arrived, from Brasil to New Zealand. https://twitter.com/DemitasseNZ/status/884599021980991488 The book seems to be a beloved companion during the summer holiday. Christian Mohn and Erik Bussink engaged in a competition to provide us the best vacation shot possible. Mohn: https://twitter.com/h0bbel/status/886158966018977793 Bussink https://twitter.com/ErikBussink/status/886501115201818624 Brad Tompkins of the VMUG organization joined the party by giving away twenty copies to the audience of the Indy VMUG last week. https://twitter.com/kmruddy/status/887293261714522112 Amazon awarded the book with many accolades, being the number one book in the network section and at one point it was in the top 25 of computer books overall. Quite an achievement! The absolute fantastic reviews help a lot. Thank you all for submitting a review! Due to the popularity of the book, Amazon offered us help with creating an ebook version of the book. They put their professional team to work two weeks ago, and we expect to have it online soon. Stay tuned!
KINDLE EBOOK HOST DEEP DIVE AVAILABLE
Funny enough I’ve just published an article announcing the major milestone of 4000 hard copies sold within the first month of release. I just received confirmation that the Kindle e-book version is available at the Amazon Kindle Store. It is scheduled to appear on various Amazon sites. Please check out your local Amazon for the best offer. Amazon US Amazon DE Amazon NL Amazon UK Amazon India The most popular e-book version of the cluster deep dive was Kindle, and therefore we focused on getting the Kindle e-book out as fast as possible. The professionals of Amazon Kindle Direct Publishing created an awesome e-book version. Go check it out.
VIRTUALLY SPEAKING PODCAST: HOST DEEP DIVE
Last Friday I had the honor to join Pete Flecha a.k.a. Pedro Arrow and John Nicholson on their always fantastic podcast Virtually Speaking. Together with Niels we talked about what it takes to write a book such as the VMware vSphere 6.5 Host Resources Deep Dive. Thanks John and Pete for having me on again. Check it out. https://soundcloud.com/virtuallyspeakingpodcast/episode-49-host-resources-deep-dive
EXPLORING THE CORE MOTIVATION OF WRITING A BOOK
More than a week ago Niels and I released the VMware vSphere 6.5 Host Resources Deep Dive and the community has welcomed it with open arms. The book is finding its way across the globe, from Argentina to New Zealand. To see the massive amounts of tweets praising the books brings us pride and joy. Over the last couple of days, I have received many inquiries what it takes to write a book and if I could provide some hints and tips. I thought it might be an interesting blog post. Three questions you need to ask yourself
HOST DEEP DIVE STICKERS AND MORE
Last week we released the VMware vSphere 6.5 Host Resources Deep Dive book and Twitter and Facebook exploded. We’ve seen some pretty bad-ass pictures on our Twitter feeds such as this one by Jamie Girdwood (@creamcookie) It’s always nice to hear some praise after spending more than 800 hours on something. (When writing and self-publish a book, expect to spend over 90 minutes on one page). Thanks! The top three most often heard questions were:
WHY THE RECENT REPORTED INTEL HT BUG IS NOT IN YOUR DATA CENTER
Yesterday I tweeted out the warning message about the HT bug of Skylake and Kaby Lake processors posted on debian.org. https://lists.debian.org/debian-devel/2017/06/msg00308.html My tweet got a LOT of retweets. A lot replied with concerns about their systems. I believe most Data Centers will not suffer from this bug as it is present on Skylake and Kaby Lake processors. What is the Bug? According to the warning: Unfixed Skylake and Kaby Lake processors could, in some situations, dangerously misbehave when hyper-threading is enabled. Disable hyper-threading immediately in BIOS/UEFI to work around the problem. Read this advisory for instructions about an Intel-provided fix. https://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200v5-spec-update.html Unlikely Present in Your Data Center The reason why I believe most systems in data centers are not hit by this bug is that it solely applies to E3 Xeons from the Skylake microarchitecture. E3 CPUs are designed to operate in a single socket system, they have no QuickPath Interconnect. Therefore unable to create a symmetric multiprocessing system. The current E5 (dual-socket) system is based on the Broadwell microarchitecture. The Skylake microarchitecture is expected to appear within the next couple of months. According to the report, they will have the fix included when the product launched. If you are running a NUC in your lab, you might want to check to see whether your system might hit that bug http://ark.intel.com/products/codename/82879/Kaby-Lake http://ark.intel.com/products/codename/37572/Skylake The link will forward you to a perl script that can help detect if your system is affected or not. Many thanks to Uwe Kleine-König for suggesting, and writing this script. https://lists.debian.org/debian-devel/2017/06/msg00309.html -
KEYNOTING DEUTSCHE VMUG AND LONDON VMUG
Later on this month, I will be attending the Deutsche VMUG and the London VMUG. As part of the events, I have the opportunity to deliver the keynote on the upcoming service VMware Cloud on AWS. Many of you will already be aware that Niels and I are releasing the VMware vSphere 6.5 Host Resource Deep Dive. Together we will provide a session at both events zooming into ESXi hosts designs, highlighting some interesting behavior from a component and VMkernel perspective. DEUTSCHE VMUG USERCON 2017 14 June 2017 KAP Europa, Kongresshaus der Messe Frankfurt Osloerstrasse 5 Frankfurt am Main, 60327 DE LONDON VMUG 22 June 2017 10:00 AM - 5:15 PM (UTC) TechUK 10 St Bride Street London, EC4A 4AD If you can’t make it to the LONDON VMUG, join us at vBeers that night. We will be heading over to the Fourpure brewing company at 22 Bermondsey Trading Estate, Rotherhithe New Road, London Hope to see you at one of these events!
MEMORY-LIKE STORAGE MEANS FILE SYSTEMS MUST CHANGE - MY TAKE
I’m an avid reader of thenextplatform.com. They always provide great insights into new technology. This week they published the article “Memory-Like Storage Means File Systems Must Change” and as usually full of good stuff. The focus of this article is about the upcoming non-volatile memory technologies that leverage the memory channel to provide incredible amounts of bandwidth to the storage medium. I can’t wait to see this happen and we can start to build systems with performance characteristics that weren’t conceivable a half a decade ago. The article mentions 3D XPoint and Intel Apache Pass is the codename for 3D XPoint in DIMM format. It could be NVDIMM it could be something else. We don’t know yet. This article argues that storage systems need to change and I fully agree. If you consider the current performance overhead on recently released PCIe NVMe 3D XPoint devices, it is clear that the system and the software have the largest impact on latency. The solved the device characteristics pretty much; it’s now the PCIe bus and the software stack that delays the I/O. Moving to the memory bus makes sense. Less overhead and almost five times the bandwidth. For example, four-lane PCIe 3.0 provides a theoretical bandwidth of close to 4 GB/s while 2400 MHz memory has a peak transfer rate of close to 19 GB/s. This sounds great and very promising, but I do wonder how will it impact memory operations. The key is to deliver an additional level of memory hierarchy, increasing capacity while abstracting the behavior of the new media. It’s key to understand that memory is accessed after an L3 miss. It can spend a lot of time waiting on DRAM. A number often heard is that it can spend 19 out of every 20 instruction slots waiting on data from memory. This figure seems accurate as the latency of an instruction inside a CPU register is one ns while memory latency is close to 15 ns. Each core requires memory bandwidth, and this impacts the average memory bandwidth per core. Introducing a media that is magnitudes slower than DRAM can negatively affect the overall system performance. More cycles are wasted on waiting on memory media. Please remember that not every workload is storage I/O bound. Great system design is not only about making I/O faster; it’s about removing bottlenecks in a balanced matter. It’s essential that the storage I/O should not interrupt DRAM traffic. An analogy would be a car that can go 65MPH. The car in front of him drives 55 MPH. By selecting another lane, the slower car does not interfere anymore, and he can drive the speed he wants. The problem is in this lane cars typically drive 200 MPHs. The key point for both NVDIMM as Intel Apache Pass is that adding storage on the memory bus to improve I/O latency should not interfere with DRAM operations. This content is an excerpt of the upcoming vSphere 6.5 Host Resources Deep Dive book.
VIRTUALLY SPEAKING PODCAST: VMWARE CLOUD ON AWS & HOSTDEEPDIVE
Last Friday I had the honor to join Pete Fletcha a.k.a. Pedro Arrow and John Nicholson on their always fantastic podcast Virtually Speaking. Unfortunately, John was ill that morning, but Duncan helped us out by taking a break from his vacation. We spoke about the upcoming service VMware Cloud on AWS (#VMWonAWS). Why it bring such a tremendous value for customers who are in the process of building a hybrid cloud, and how it can help organizations who are already a customer of both VMware and AWS. Closing off we touched upon the progress of the upcoming book ‘vSphere 6.5 Host Resources Deep Dive’. I had a blast being a guest again, enjoy the show! https://soundcloud.com/virtuallyspeakingpodcast/episode-43-vmware-cloud-on-aws?utm_source=soundcloud&utm_campaign=wtshare&utm_medium=Twitter&utm_content=https%3A//soundcloud.com/virtuallyspeakingpodcast/episode-43-vmware-cloud-on-aws
IMPACT OF CPU HOT ADD ON NUMA SCHEDULING
On a regular basis, I receive the question if CPU Hot-add impacts CPU performance of the VM. It depends on the vCPU configuration of the VM. CPU Hot-Add is not compatible with vNUMA, if hot-add is enabled the virtual NUMA topology is not exposed to the guest OS and this may impact application performance. Please note that vNUMA topology is only exposed when the vCPU count of the VM exceeds the core count, thus if the ESXi host contains two CPU packages with 10 cores, the vNUMA topology is presented to the VM if the vCPU count equals 11 or more.