VMotion

Peripheral virtualization for VMware environments

On SearchServerVirtualization.com, I wrote a tip about virtualizing server I/O. In this video blog, I want to explain a few points specific to VMware environments for peripheral virtualization, including devices that help with difficult system conversion projects.

Performance tips from the summer New England VMUG; attendees sound off

425 IT geeks invaded Brunswick, Maine last Thursday for the New England VMware Users Group summer meeting at Brunswick High School. The event, which started at 10 AM with a sponsor showcase and proceeded with after-lunch sessions, concluded in a Lobster/Clambake at Gritty’s in Freeport, Maine.

 “Good performance starts with proper planning and design, configuration best practices and operational awareness,” said Mike Burke (left), Virtual Infrastructure Practice Director for Virtera, a CT-based consulting firm during the first session I attended equivocally titled “Getting the most out of your ESX Environment – Performance tuning.”

“Tuning is not a replacement for proper planning and design,” Burke said. “Don’t guess; gather the data.”

Planning trumps tuning in VMware deployments
Performance, Burke said, hinges on examining and understanding how CPU, memory, networking and disk space will work together in a virtual infrastructure. Planning, then, is the key to better ESX performance, and not necessarily tuning.

Generally speaking, more cores are better; so plan on going big. “How does VMware license their product? Per socket. If you can choose a quad-core, it’s a lot more economical,” Burke said, citing that AMD series processors are now “dirt cheap” compared to earlier years, with eight core boxes going for around $2000.

“You need to weigh what the workload is against what the goals of virtualizing it are,” Burke said. For example, a four-CPU physical server may not be a good candidate for a server consolidation project if it’s currently using the four CPUs to the fullest extent, because you won’t have a good consolidation ratio on those systems. It may, however, be a candidate if the goal is overall server virtualization instead of consolidation.

Another reason for this type virtualization is hardware capability. You can’t VMotion from AMD to Intel. Even in servers from the same line, Burke said, older hardware instruction sets coded in the CPU won’t look the same, preventing VMotion capability.

More host RAM gives better overall performance, configure a VM’s memory based on actual need – are you really using the full two GHz, or would it better used elsewhere? On a general note, though, Burke said “oversubscribing,” or provisioning more memory for virtual machines in the physical host server, is better than not.

Advanced configurations
A systems administrator can, however, tweak a few advanced variables in a virtual machine’s configuration or vmx file. For memory, you can reset the time interval for transparent page sharing (TPS), which is automatically set at 60 seconds, by using mem.ShareScanTime. Adjust the memory pages to scan per 1 GHz idle cycle, automatically set at 4 MB/sec per 1GHz by using mem.ShareScanGhz. mem.CtlMaxPercent limits memory reclamation by ballooning.

But tweaking these parameters, Burke warned, can detract from virtualizing your systems. “You’re instructing ESX to spend more time processing and looking for memory savings rather than sitting in the background and running the VMs, which diverts resources away from virtualizing guests to handling these configurations on the backend.”

On a per-VM level, you can use the same mem.CtlMaxPercent command, and also: sched.mem.maxmemstl, which caps the max memory reclamation by ballooning (vmmemctl); sched.mem.pshare.enable – enables/disables memory sharing (TPS); lastly, using sched.swap.persist can enable vSwap to persist after power-off.

New England VMware Users Group summer meeting attendees sound off
Other sessions spanned from technical sessions about VMware DRS and HA to VDI demonstrations, SRM implementation and general topics, such as managing the virtual data center and how to minimize VM sprawl. Some sessions were led by speakers from consulting companies; others were 45 minute long vendor sales pitches disguised as learning sessions, but overall attendees had a good experience.

“For me, the sessions are good, but I can learn the same material in a textbook or on a website,” said Lee Pullen of the Maine Education Association. “The largest benefit is the networking, meeting other users and finding out what they’re doing in their own environments. That’s the real value in attending.”

“I found a few of the titles of the sessions misleading,” said State of Maine Office of Information Technology employee Lori Blier. “The last session I was at seemed like it was going to be about getting more out of your virtual infrastructure, which is what it was called. But they mainly talked about virtual desktops.”

Perhaps next year, the organizers could include descriptions of the presentations so that participants know exactly what to expect, Blier suggested. She said that she liked the sessions that discussed managing and using ESX Server, which is what the state of Maine plans to upgrade to pending management approval. They currently use VMware Server in production.

“I was a little disappointed that there were no sessions or vendors that focused on the networking side,” commented Kris Kirby from the Vermont Agency of Natural Resources, who said that’s his main concern with his VMware environment. “I also thought it was going to start a little earlier.”

Chris Harney, a systems engineer from Maine who organizes the New England Users Group meetings, said that feedback from the last session indicated increased interest in virtual desktop information sessions, which is why several of the sessions catered to that track. He also said that if networking came up as a trend on the feedback sheets, it would be voted on by a focus group and most likely included in the program for the January winter meeting, which will be held in Massachusetts.

“We’ve only been doing this for a couple years, and we’re still trying to figure out what works,” Harney said. “This is just a hobby for me, but it’s almost a full-time job. When we first started, we had 35 people. Now we’re looking at almost 500 per meeting.”

Virtualization virtual tradeshow offers VMware networking opportunities

Trade shows are great – if you have time to attend, have staff to cover while you’re away learning about a new technology, can avoid summons back to the office during the show, can find a show in your local area or can get budget approval to attend a show that requires flight or hotel reservations.

Enter the virtual trade show (VTS); an online conference conceived to mitigate the above challenges. Last week, sister sites SearchDataCenter.com and SearchServerVirtualization.com hosted an advanced enterprise virtualization VTS. I helped staff the networking lounge and editorial booth where I had the opportunity to chat with VMware users about two of the virtualization provider’s newest tools, Site Recovery Manager (SRM) and Storage VMotion.

IM chatting with attendees
Conversations ranged from general IT talk (“Anyone use virtual desktops?”) to small talk (“What’s the weather like in Maine?”). Trying to be the friendly host, I said “Good morning” to the room. I immediately got the reply “Good evening” and was subsequently told this particular user was signed on from –literally–the other side of the world.

I ended up chiming-in on another user’s question about if anyone was familiar with VMware Site Recovery Manager (SRM). The respondent had said that he was, and I ended up asking him about his experience via private IM. SRM orchestrates your virtual machine disaster recovery (DR) plan in the event that your main data center goes down. It prioritizes which virtual machines (VMs) are brought up at the failover site based on available resources, syncs your VM configurations between the main site and the failover site, and allows for DR plan testing without having to take the system offline. It’s a relatively new addition to the VI3 lineup, having been on the market for four months (at the time of publication).

Our conversation turned to plug-ins, and he raved about Andrew Kutz’s Storage VMotion plug-in. The plug-in adds a user interface to the out-of-the-box product, which operates through a command line interface. The attendee explained that he’s primarily a “Windows guy,” so a graphical user interface makes using Storage VMotion much easier.

Kutz recently released an update to the Storage VMotion plug-in.

“The new release now ignores raw device mapping,” Kutz said. “Previously, if you had a raw device that pointed to a 300 Gig disk, the plug-in would look at it as an actual disk and screw up the disk size map.”

He also removed the majority VMware’s internal code from the plug-in (excepting the code that loads the plug-in), replacing it with code based on the VI Toolkit for .NET.

Impressive user interface
The VTS emulates the look of a physical tradeshow floor, which makes navigation a bit friendly, though not as intuitive as I would have liked. You could either move around with the help of a clickable navigation bar, or point-and-click your way from the main entryway to the desired location, be it the conference hall, vendor hall, networking lounge or “library” where you can download PDFs of presentations and various information from vendors, which then moves into your “suitcase,” displayed on your personal page.

VTSs are essentially fancy webcast packages displayed in unconventional ways. In this particular show, the topics were “Protecting your Virtual Environment: Backup and Storage,” “Virtual Infrastructure Automation and High Availability Best Practices” and “Virtual Infrastructure Tuning and Advanced Management.” The speaker was displayed on the left side of the screen presenting his slides via streaming video. The slides were displayed on the right hand side. Users could ask questions via a box at the bottom of the screen.

The VTS, if done correctly, has many more plusses than minuses. As long as there is a reliable Internet connection, there’s no need to leave the data center (if you don’t have a reliable connection in your data center, you might think about leaving for good). The content is almost exactly the same as at a physical trade show (that’s how they got the video of the speaker to begin with). And editorial staff can send IT pros direct links to helpful guides that they know of if an IT pro wants to know about, for example, virtual desktop drawbacks.

If any SearchVMware.com readers passed up the opportunity to “attend” a virtual trade show, I suggest you test it out next time a topic of interest comes around. It’s actually fun to use (think AOL in the 90’s minus the “you’ve got mail”) and offers great learning potential and networking opportunities.

An archived version of the advanced enterprise virtualization virtual trade show is available online, short registration required.

What makes VMotion so great?

To many of us, some VMware product features and functionalities still seem like magic. Sure, I understand what the products do, but considering that my education and background is in writing and editing (read: not computer science), how they work still remains a mystery.

At least a few pieces of the VMware Infrastructure feature set were explained to me by Alliance Technologies solutions architect and Central Iowa Virtualization User Group (CIVUG) member Sean Clark. In a recent conversation, Clark explained how VMotion works, what Distributed Resource Scheduler (DRS) is and how the competition stacks up. Check out this audiocast if you’re still using VMware Server or just the ESXi hypervisor but are considering moving into the rest of the suite as it more provide more information to help you with your decision.