System Administration Archives

A Look at VMware Licensing & Environment Growth

July 14, 2011 by Bob Plankers

My previous post on VMware licensing changes focused mainly on the question of “will I be able to upgrade my current setup to vSphere 5?” I concluded yes, easily, and if you would like to see how I did it I encourage you to go read the post. It’s pretty obvious that futures will change, though. I’ve always subscribed to the “fewer bigger machines” theory, to which I owe a lot to Steve Chambers. Some of his writings espoused the idea that most IT failures are human error, to which I agree. Coupled with that is the idea that the cost of a server isn’t in the price, it’s in the management of it. So why have more machines, more …

The Five Stages of VMware Licensing Grief

July 12, 2011 by Bob Plankers

Update 8/3/2011: VMware announced updated licensing terms (link is to my post on the matter). As part of the vSphere 5 & Cloud Infrastructure Suite announcements today VMware announced a new licensing model. And, as expected, people are having a fit. A few of us were briefed on this new model last week, and I’ve got a four-day head start on the denial, anger, bargaining, depression, and acceptance that seems to follow this change. Let me work through it with numbers from my environment, as an IT professional, in a professional way. Hopefully this will let some people pass from the anger stage to bargaining (perhaps with their VMware sales representatives) and on to acceptance. Before I start, I do …

Two Things I Really Would Like From Mozilla Thunderbird

July 5, 2011 by Bob Plankers

While I was on vacation I noticed that the Mozilla Foundation released Thunderbird 5.0. From the release notes it’s clear that a lot of cleanup work happened with this release, improving “speed, performance, stability and security,” but not very many new or revolutionary features. I like Thunderbird a lot, and I like that they’ve focused on stability more, but I still have two feature requests for future releases. Multi-client synchronization The promise of IMAP is that you are able to check your email anywhere, and it can stay on the server. There are also some nice things about thick email clients, like better searching, easy junk mail processing, offline modes, etc. The problem lies in having two copies of Thunderbird …

Why "Bring Your Own Device" Is Seriously Flawed

June 3, 2011 by Bob Plankers

I was reading Larry Dignan’s ZDNet article (link at the end) on the security implications of Bring Your Own Device (BYOD), and thought I’d take it a bit further. For a while now I’ve been thinking that BYOD has some serious issues in general, and is specifically a symptom of the ongoing war between risk-averse IT and personal productivity in the enterprise. 1. A company still has to provide computing equipment to everybody who doesn’t BYOD. Lots of people aren’t going to bring their own device, because they don’t have one, or aren’t paid enough to buy one. As such, a company is going to have to provide them one anyhow. 2. Everybody is going to buy all sorts of …

Dell, SSD, CacheCade, and H700/H800 Controllers

June 1, 2011 by Bob Plankers

Dell’s announcement last week that their rebranded LSI RAID controllers, the H700 & H800, now have the ability to use certain local SSD disks as a read cache tier. This is the “CacheCade” technology LSI has offered since September 2010, and looks functionally similar to technologies like NetApp’s FlashCache, where SSD maintains a copy of “hot” blocks on the fast storage. There are some limitations to it, namely that it will require the H700/H800 models with 1 GB of NVRAM on them, and comes as part of a certain firmware level. The feature will also only work with certain SSDs from Dell, so you can’t plan to just cram a cheap Intel X-25 in there (which is unfortunate, in my …

UNIX Utility of the Day: watch

April 26, 2011 by Bob Plankers

Not a lot of people know about the ‘watch’ command, part of the standard complement of GNU tools available on most Linux distributions, as well as many Linux-like OSes such as VMware ESX and the VMware vMA. Simply put, it runs a command at a specific interval for you. So if you want to continually see the number of httpd processes running on a host you could use: watch ‘ps -ef | grep httpd | wc -l” Or maybe you want to watch the temperature on a remote physical host using IPMI. The -n flag changes the number of seconds between the commands: watch -n 60 -d ‘ipmitool -I lan -U username -P password -H host-bmc.address sdr type “Temperature”‘ The …

How To Disable Teredo IPv6 Tunneling in Microsoft Windows

April 25, 2011 by Bob Plankers

Greg Ferro’s post about how Microsoft Teredo is a suboptimal networking solution made me think it’s time to update my old post on how to disable Teredo in Windows 7 and in Windows 8. For the record, I agree — I’ve had serious problems with it conflicting with my native IPv6 connectivity. 1. Open a command prompt with administrator privileges (Start->Accessories->right click on Command Prompt, choose Run as Administrator): 2. Issue the command: netsh interface teredo set state disabled 3. You may need to reboot, depending on your version of Windows. If you wish to re-enable Teredo at some point you can issue the command: netsh interface teredo set state type=default

VMware Fault Tolerance, Determinism, and SMP

April 19, 2011 by Bob Plankers

We’re all at least roughly familiar with Fault Tolerance, a feature VMware added to vSphere 4 to establish a mirrored VM on a secondary host. It’s kind of like RAID 1 for VMs. To do this, Fault Tolerance records the inputs to a primary VM, and then replays it on the secondary VM to achieve the same results. There are two important and somewhat subtle points here that help us understand why Fault Tolerance is limited to one CPU. First, the process records the inputs, not the state of the PC after the inputs happen. If you moved the mouse on the primary it moves the mouse on the secondary VM in exactly the same fashion. If you ping the …

Check Your Work

April 1, 2011 by Bob Plankers

It often pays to have someone else look at your work, if only for a moment.

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