Yellow Bricks

by Duncan Epping

Spotted a RUN DRS t-shirt at VMworld and wondering where to buy them?

· ·

I had so many people ask about these RUN DRS shirts I had made in the last weeks… Unfortunately it was a limited print so I cannot offer them, and to be honest I don’t really want to sell them either. Frank created the design and I asked Frank if it would be okay to share it so that everyone who wants one can get it printed themselves.

Frank just published a blog post which contains the details around how to make your own logo, and he also posted the “PSD” file. (Photoshop format) This idea is free for use, however you should not use this design for commercial purposes. Feel free to get a batch printed, maybe work with some local VMUG folks… I am sure they will be a big hit!

 

Can I get your book for free?

· ·

Well not from me, but CloudPhysics has a nice book give-away going on at the moment for the VMworld Barcelona attendees! So what do you need to do?

How To Win

  • Email us at info@cloudphysics.com with a subject of “Book”. No message is needed.
  • Register at http://www.cloudphysics.com/ by clicking “SIGN UP”.
  • Install the CloudPhysics Observer vApp to activate your dashboard.

Eligibility

  • You are attending VMworld Barcelona.
  • You are a new CloudPhysics user.
  • You fully install the CloudPhysics ‘Observer’ vApp in your vSphere environment.

That is an easy way of getting the book for free right? So I suggest you head over and sign up to make sure you are part of the first 150 users that gets a free book!

Cool iPad app: VMware Mobile Knowledge Portal

· ·

We’ve just published a cool application, it is called the VMware Mobile Knowledge Portal.

Description
The Mobile Knowledge Portal gives you access to VMware marketing and technical content. Use the application to watch installation videos, read product whitepapers, and learn best practices.

I think this is a very useful app for those who like to have a centralized place for all their tech content. This is going to grow soon and be expanded in to various areas. Just go out and download it, try it and leave some feedback here!

Some questions about Stretched Clusters with regards to power outages

· ·

Today I received an email about the vSphere Metro Storage Cluster paper I wrote, or better said about stretched clusters in general. I figured I would answer the questions in a blog post so that everyone can chip in / read etc. So lets show the environment first so that the questions are clear. Below is an image of the scenario.

Below are the questions I received:

If a power outage occurs at Frimley the 2 hosts get a message by the UPS that there is a power outage. After 5 minutes (or any other configured value) the next action should start. But what will be the next action? If a scripted migration to a host at Bluefin starts, will DRS move some VMs back to Frimley? Or could the VMs get a mark to stick at Bluefin? Should the hosts at Frimley placed into Maintenance mode so the migration will be done automatically? And what happens if there is a total power outage both at Frimley and Bluefin? How a controlled shutdown across hosts could be arranged?

Lets start breaking it down and answer where possible. The main question is how do we handle power outages. As in any datacenter this is fairly complex. Well the powering-off part is easy, powering everything on in the right order isn’t. So where do we start? First of all:

  1. If you have a stretched cluster environment and, in this case, Frimley data center has a power outage, it is recommended to place the hosts in maintenance mode. This way all VMs will be migrated to the Bluefin data center without disruption. Also, when power returns it allows you to do check on the host before introducing them to the cluster again.
  2. If maintenance mode is not used and a scripted migration is done virtual machines will be migrated back probably by DRS. DRS is triggered every 5 minutes (at a minimum). Avoid this, use maintenance mode!
  3. If there is an expected power outage and the environment is brought down it will need to be manually powered on in the right order. You can also script this, but a stretched cluster solution doesn’t cater for this type of failure unfortunately.
  4. If there is an unexpected power outage and the environment is not brought down then vSphere HA will start restarting virtual machines when the hosts come back up again. This will be done using the “restart priority” that you can set with vSphere HA. It should be noted that the “restart priority” is only about the completion of the power-on task, not about the full boot of the virtual machine itself.

I hope that clarifies things.

Restoring an iPad that is in perpetual recovery mode

· ·

My iPad crashed a couple of weeks back… and as this is the iPad that my kids used it was code red! I tried powering it on but the screen remained black. I figured I was completely out of battery so attached it to the charger for hours but still nothing.

Next I tried the old “holding the home + sleep button for 15 seconds” trick, but that didn’t do anything either. Still a black screen. I hooked the iPad unto my Macbook after charging it again for 8 hrs and leaving it alone for another 8. (not that it probably has anything to do with the solution, but I figured I would document the full process…)

iTunes now said that my iPad was in recovery mode. So I figured I would hit “okay” and do a “restore” as iTunes suggested. After going through the full restore cycle my iPad “rebooted” (screen still black so who knows what it did) and it still said it was in recovery mode”. Again no luck. I tried the same procedure on a different PC, this time using Windows… but again no luck. After googling for a while I stumbled on a procedure that actually worked. All credits go to wikidot for writing this up, but this what I had to do to get it working again:

  1. Launch iTunes
  2. Connect ipad to Macbook
  3. Press and hold for 3 seconds Sleep/Wake button.
  4. After 3 seconds, keeping hold on Sleep/Wake press Home button for 10 seconds.
  5. Release Sleep/Wake one, but hold Home button for another 15 seconds.
  6. When “iTunes has detected …in recovery mode..” message appears on computer screen press OK.
  7. Press SHIFT+CLICK (PC) or ALT+ CLICK on the restore button.
  8. Choose from the opened file dialog the ipsw-file you downloaded. Click Open it. The flashing will begin. Once more, never touch your iPad / iPad 2 / iPad 3 or computer. Let them to complete the job. The tablet will restart itself to complete the firmware flashing.
  9. Wait and your iPad will be as new

** you can find the “ipsw-file” via iClarified, it basically is a firmware file for your iPad, or google it! **