Inquisitive

VMware Tip 6: Configuring paravirtualized SCSI (PVSCSI) for boot disks (Win 2003 & 2008) in ESX & ESXi 4

With vSphere 4.0 update 1, PVSCSI adapter can be used for boot disks of virtual machines and it is supported for Windows 2003 & 2008 guest OS. Since Windows doesn't have drivers for this SCSI adapter, you will get "Setup did not find any  Hard Drive Installed on your computer" error during installation. 

The following floppy images are available - pvscsi-1.0.0.5-signed-Windows2003.flp,  pvscsi-1.0.0.5-signed-Windows2008.flp & vmscsi-1.2.1.0-signed.flp in /vmimages/floppies of ESX host

Edit the virtual machine floppy settings. From the floppy options, select use floppy image and browse to the vmimages/floppies/pvscsi-1.0.0.5-signed-Windows200x.flp. Do not connect it now (doing so may result in a blank screen in the console, when the VM is powered on)

During the Windows OS installation, press F6 and connect the floppy now from settings. Press S & PVSCSI driver should appear. Press Enter to continue.

For using PVSCSI in ESXi, please refer to this community post - http://communities.vmware.com/thread/243972?tstart=0

Please refer to this VMware KB on how to configure disks with PVSCSI - http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1010398

Update: Good information on why PVSCSI doesn't improve performance in few cases - http://communities.vmware.com/thread/213313

 

iPhone 3GS - Thermal Images

Infrared Thermography is an exciting technology with lots of applications ranging from predictive maintenance, defense, medical and now to find out my iphone's body heat signature

When iphone 3GS was launched, there were few reports of iphone getting overheated. Whether the reports were true or not, apple released an advisory on keeping the iphone within operating temperatures. You can read that here  - http://support.apple.com/kb/HT2101. Even there is a temperature warning screen built in.

    

So I picked up my thermal camera and prepared to do a test with my iphone 3GS which includes taking a image after a period of charging and another image after using the phone intensively for some time by playing games and watching videos. The tests are to find out the hotspots and maximum temperature that the phone is reaching after a period of normal usage.

The thermal images below shows the hotspots of iphone 3GS taken after ten minutes of usage. To put the thermal images in context, I had attached a terrible paint brushed image below. I am pretty sure that the big red spot is because of battery but not sure about the spot at bottom right corner, when you face the back of iphone towards you. I had searched ifixit 3GS tear down but couldn't figure out what causes it to overheat at that particular spot. But there is nothing to worry about as it is within the operating temperature but I am just curious to know. 

 If you are aware, please comment.. 

     

            

But I never felt that my iphone is overheating.. Do you??

Snow Leopard..... Rawrrrrrrrrrrrrss

I had recieved my Snow Leopard DVD, a day before what Apple had promised. My Mac fleet includes a 13.3" Macbook aluminium and a 13.3" Macbook Pro. Since the Macbook pro was bought recently, I was eligible for the Apple Up to Date program and I got my upgrade disk for just 9.95$

You can get yours here if you are eligible >> http://www.apple.com/macosx/uptodate/

My Macbook pro has 4 gigs of memory and it took nearly 45 mins for the upgrade to complete. I didn't face any glitch during the upgrade process. 

Then came the surprise.. I didn't notice much new visually when I booted into Snow Leopard. My bad.. I remembered what Apple had said.. Refined not re-invented. Let's look at some of the great improvements..

Technology Improvements :

  Invented to take full advantage of today's multicore and multiGHZ processors.  It helps developers to develop applications that runs efficiently on multicore systems. For a normal user, will experience the speed and performance of new generation applications

        Now you can have tons of RAM for your Mac (upto 32 gigs) now with Snow Leopard than just 4 gig before. With 64 bit you can crunch twice the data per clock cycle. All your inbuilt OS X applications are 64 bit. Again a normal user will experience the significant performance in designed for 64-bit applications

  Again a developer stuff and now developers can leverage the gigflops of computing power available in new gen graphics cards

  Shame on you Microsoft !!

 The Chinese character input is cool, an innovative use of the touchpad 

As promised, I had gained back few gigs of hard disk space. Some say it's because of new math that Apple is using for Snow Leopard. Overall there are nice improvements, small and big everywhere.

Good reviews :

http://www.engadget.com/2009/08/26/snow-leopard-review/

http://gizmodo.com/5346418/snow-leopard-review-lightened-and-enlightened?skyline=true&s=x

Snow Leopard Rawrrrrrrrrrrs!!

HFT.. Yikes!! Time to buy a supercomputer to make pennies

HFT (High Frequency Trading) is the latest buzz of wall street. You know what.. computers are earth's biggest stock trader and an estimated 70% of trading volumes are generated by computers trading against one another. Those who have the best code and tons of computer chip wins.

At stake is billions of dollars for the Wall st giants and they are using computers to bully small investors like me.. It's time to buy a super computer to make my pennies.

From FT..

The technology essentially involves automated tick-by-tick, high turnover buying and selling, which relies heavily on the speed and sophistication of the network and computer systems involved. These are lightning fast and voluminous trades to take advantage of minute and fleeting changes in prices. Speed is obviously essential — as is beating the competition to an arbitrage opportunity.

Great HFT articles..

http://opinionator.blogs.nytimes.com/2009/07/24/weekend-opinionator-is-wall-street-picking-our-pockets/

http://arstechnica.com/tech-policy/news/2009/08/nyse-builds-computer-trading-mothership-worries-abound.ars

http://arstechnica.com/tech-policy/news/2009/07/-it-sounds-like-something.ars

http://ftalphaville.ft.com/blog/2009/07/08/60761/the-cold-war-in-high-frequency-trading

http://opinionator.blogs.nytimes.com/2009/07/24/weekend-opinionator-is-wall-street-picking-our-pockets/

Haaaaeeeehhhhhhh!! I am going to MARS!!

VMware Tip 5: vSphere Volume Grow Tips & Tricks

vSphere volume grow allows dynamic expansion of a VMFS volume without disrupting the virtual machines running on that datastore. 

The underlying LUN on the storage array should be extended first which is then made available to the ESX host. There are two possibilities here - Extend the same LUN in the storage or create a new LUN and add it as an extent. Extending the same LUN may or may not improve performance based on how the LUN is laid out on the spindles. This method will have less management complexity and safer as there is only one LUN to protect

Creating a new LUN to add as an extent will improve performance if they are laid out on different spindles on the array. This adds more LUNs to manage and the datastore will be inaccessible even if one LUN is corrupted. So there are more LUNs to protect & manage.

With VI3, creating a new LUN in the array and adding it as an extent will work without the need to turn off the VMs. Extending the same LUN will not work when the VMs running on the VMFS volumes are powered on. A simple workaround is to do a storage vMotion to extend the same LUN

With vSphere, there is no need to turn off the VMs to extend the same LUN in the storage array.

VMware Tip 4: Thin provisioning with vSphere - Tips & Tricks

With vSphere 4, thin provisioning was supported at virtual disk level through vCenter GUI. With thin provisioning, networked storage space utilization is improved because of dynamic allocation of storage to the virtual machines. vSphere has built in capabilities to provision, manage and monitor thin provision storage to virtual machines

Thin Provisioning Tips & Tricks :

• Monitoring the datastore space utilization is very critical to prevent running out of space by overcommitment. Leverage vSphere Datastore alarms like "Datastore usage on disks" and "Datastore disk overallocation %" to trigger alerts
  
• Take virtual disk size, snapshots, swap and other files into consideration while planning for storage space for datastores and not just virtual disk size
  
• Avoid running guest OS disk defragmentation programs on a virtual disk which is thin provisioned as it might inflate the disk. Using storage vMotion using thin option will defragment the virtual disk
  
• Use storage vMotion to convert a existing thick virtual disk to thin
  
• Use thin/virtual provisioning at storage array also if it supports for better efficiency
  
• Enable alerts on the storage array to monitor the utilization of thin filesystem/LUN 
  
• As deleting data inside the virtual disks cannot claim the space back, storage vMotion using thin option can be used to make the disk thin again. 
  
• VMware FT cannot be used with thin provisioned virtual disks. Enabling FT will make the virtual disks thick
  
• Avoid using thin virtual disks for applications in guest os which zeroes out the space before actually writing into it
  

Different virtual disk formats :

Thin - vmkernel allocates space only before an I/O is committed. Virtual disk size will be equal to the utilized size and will grow till the user specified size

Zeroed Thick - vmkernel zeroes out the required free space only before an I/O occurs. Virtual disk size will be equal to the user specified size during virtual disk creation

EagerZeroed Thick - vmkernel zeroes all the free space during the creation of virtual   disk. Virtual disk size will be equal to the user specified size during virtual disk creation

VMs having virtual disk with thick formats can be converted to thin format using storage vMotion in vSphere

Great Thin provisioning resources :

http://virtualgeek.typepad.com/virtual_geek/2009/04/thin-on-thin-where-should-you-do-thin-provisioning-vsphere-40-or-array-level.html

http://itknowledgeexchange.techtarget.com/virtualization-pro/pointers-for-using-thin-provisioned-disks/

http://www.vmware.com/files/pdf/thin_provisioning_datasheet.pdf

Potentially game changing !!

Here's some medical breakthrough : three patients had their sight restored in less than a month bycontact lenses cultured with stem cells. All three patients were blind in one eye. The researchers extracted stem cells from their working eyes, cultured them in contact lenses for 10 days, and gave them to the patients. Within 10 to 14 days of use, the stem cells began recolonizing and repairing the cornea.

http://www.theaustralian.news.com.au/story/0,25197,25550134-2702,00.html

vSphere Available now !!

The much awaited VMware's Cloud operating system is ready for shipping now

                          

    http://www.vmware.com/products/vsphere/

          

Google Opens up it's data center and server secrets

Google recently hosted the "Efficient Data Center Summit" to discuss the best practices to improve the data center energy efficiency

All Videos and presentations are posted in the following Google official site >>

http://www.google.com/corporate/green/datacenters/summit.html

The summit also includes a good April fool joke