iOS 7: How to get your WiFi working again

In addition to battery issues, many of the complaints I've heard about iOS 7 center around WiFi. After upgrading, many people are getting the dreaded "unable to connect" message. There is a solution that's been passed around on the Apple discussion forums that should work for most people. You'll need to spend a couple minutes with your phone and router.

Put your phone into Airplane Mode. Then, go into Settings > General > Reset > Reset Network Settings. Then, reboot your router if you have access and take your phone out of Airplane Mode. You'll be prompted to join your network again, and it should work this time.

You can do this with Airplane Mode turned off, but several people on the forums say they've had better luck with Airplane Mode on.

Did you have this issue? Did this work for you, or did another method help? Let us know in the comments.

iOS 7: How to get your WiFi working again originally appeared on TUAW - The Unofficial Apple Weblog on Mon, 23 Sep 2013 15:30:00 EST. Please see our terms for use of feeds.

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VMware vSphere Blog: vCenter Single Sign-On 5.5 Not Recognizing Nested Active Directory Groups

I was testing vSphere 5.5 upgrades in my lab and came across an interesting situation that you need to be aware of. In a nutshell, pay attention to how your Active Directory groups are configured on your vCenter Server and avoid nesting any domain level user or group accounts inside of local groups.

Heres the situation I ran into. My lab was running a vanilla vCenter 5.1 install. In vCenter I only had one permission assigned, which is for the local Administrators group.

With this setup I was able to login with any user who was a member of the local Administrators group. This included *both* the local administrator account as well as the domain administrator account. The reason the domain administrator was able to login is because when my vCenter server joined the AD domain the Domain Admins group was automatically added as a member of the local Administrators group. So the domain administrators access was obtained through a nested group membership the domain group Domain Admins was nested inside the local Administrators group, which was given permissions to vCenter.

While this nesting of a domain group inside of a local group worked with 5.1, it does not work with 5.5. I discovered this following a successful upgrade to vCenter 5.5. After the upgrade I could login as the domain administrator, but I couldnt see any objects in the vCenter inventory. (see http://kb.vmware.com/kb/2059528)

To fix this I had to explicitly assign permissions to the vCenter server for the Domain Admins group. To do this I logged in as the local administrator, selected the vCenter server, then went to the Manage and Permissions tabs. There I added full admin permissions for the Domain Admins group.

The take away here is when moving to vSphere 5.5, whether a new install or an upgrade, watch your group memberships and avoid nesting domain users and groups in with local groups. Again, more information can be found in this knowledge base article: http://kb.vmware.com/kb/2059528.

vCenter Operations Manager – Understanding Adapters


An exclusive VMworld TV interview with Jim Silvera, Expert on vCenter Operations and how adapters collect and process data.A key feature of vCenter Operations Manager Enterprise is its ability to consume data from across theenterprise. vCenter Operations Manager Enterprise uses adapters to collect data from a variety of data sources,including specific third-party products.

Adapters work with the vCenter Operations Manager Enterprise Collector to collect and process data.The Collector acts as a gateway between vCenter Operations Manager Enterprise and its adapters. The adaptersconnect to and collect data from data sources, transform the data into a format thatvCenter Operations Manager Enterprise can consume, and pass the data to the Collector for final processing.



Depending on the data source and the adapter implementation, an adapter might collect data by making APIcalls, using a command-line interface, or sending database queries. Some adapters collect data for each resourceindependently and other adapters extract data for all resources based on a specified time range.

vCenter Operations Manager Enterprise uses embedded adapters and external adapters. Embedded adaptersare the most common type of adapter implementation.

VMware Virtualization Management Blog: vCenter Operations Management Tech Tips: Tip #9 – Best Practices for vSphere Capacity Planning – Part 1 of 4

Welcome back from VMworld San Francisco 2013. We promised that we will come back and share the content from our VMworld presentations on vSphere Capacity Planning using vCenter Operations. Here is a mini-series of Tech Tips  covering:

1) picking the right metrics and knowing your operational knobs
2) picking the right visuals to understand
2a) your VM growth, Infrastructure burn rate and capacity risk
2b) how to optimize your infrastructure utilization and realize savings?
2c) determining if you have enough capacity for future growth?

Some of the patterns I am seeing across the infrastructure IT leaders are often around trying to find answers to these key questions for effective capacity planning:

i) Am I meeting my SLAs or do I have capacity risk?
   - by analyzing VM growth, infrastructure burn rate and capacity risk
ii) Can I optimize & improve infrastructure utilization & realize savings?
   - by reclaiming unused resources & increasing utilization safely
iii) Do I have enough for future growth?
   - What does my VM demand growth looks like and do I have enough or will i run out?

Working with several IT leaders, we present here how they are using vCenter Operations to get answers to the above questions. But the first step is to understand what your operational policies are across your production or test-development environments and getting the right metrics.

I take a simplistic example – over the summer, my 7 year old son fell in love with playing his Ninjago game – he played for 30-45 minutes at a stretch. But now school is on and he is ‘entitled’ to play for 10 minutes after his homework is done. His ‘demand’ – what he wants is still to play for 30-45 minutes. When he does not get what he wants, there is ‘contention’ (tantrums!).  Virtual Machines ( VMs) in vSphere are very similar to my son! Lets take the example shown below of a SQL VM configured with 16GB capacity.


Some points to note :
- What a VM is configured with is what we call ‘allocation’. What a VM demands due its OS/Application workload is ‘Demand’. What a VM gets is ‘Usage’. What a VM does not get is ‘Contention’.
So what a VM wants  = what a VM gets + what a VM does not get
Or Demand = Usage + Contention

 - If you do sizing or capacity planning based on just ‘usage’ you may be under-sizing and under planning. If you size or plan future capacity based on allocation, you may be over-sizing or over-provisioning it.

In addition, there are several metrics available in vCenter  – for different purposes – e.g. Memory consumed is a great metric to tell you how ballooning and sharing is working  – ummm. But wait it  does not tell you how much a VM wants – or what is its Demand – based on all the active pages it touches. vCenter Operations uses the concepts of Allocation, Demand etc to help you analyze the right way.

Ok, so we got the right metrics, now lets understand what are your policies to manage capacity and risk across your production or test-dev environment.

Several customers want to optimize for performance in production environment but optimize for higher density of VMs in their test-dev environment.

They over-commit CPU and Memory in test-dev but don’t over-commit in production. They have higher buffers in production etc. vCenter operations enables you to capture your ‘operational knobs’ into policies used by its analytics. It also provides out of box policies such as ‘production’ and ‘test-dev’ that can be used.

Don’t forget to check out our part 2 of this Tech Tip series on getting the right visuals to understand demand, utilization and capacity risk in your virtual environment!

VMware Virtualization Management Blog: vCenter Operations Management Tech Tips: Tip #9 – Best Practices for vSphere Capacity Planning – Part 1 of 4

Welcome back from VMworld San Francisco 2013. We promised that we will come back and share the content from our VMworld presentations on vSphere Capacity Planning using vCenter Operations. Here is a mini-series of Tech Tips covering:

1) picking the right metrics and knowing your operational knobs
2) picking the right visuals to understand
2a) your VM growth, Infrastructure burn rate and capacity risk
2b) how to optimize your infrastructure utilization and realize savings?
2c) determining if you have enough capacity for future growth?

Some of the patterns I am seeing across the infrastructure IT leaders are often around trying to find answers to these key questions for effective capacity planning:

i) Am I meeting my SLAs or do I have capacity risk?
- by analyzing VM growth, infrastructure burn rate and capacity risk
ii) Can I optimize & improve infrastructure utilization & realize savings?
- by reclaiming unused resources & increasing utilization safely
iii) Do I have enough for future growth?
- What does my VM demand growth looks like and do I have enough or will i run out?

Working with several IT leaders, we present here how they are using vCenter Operations to get answers to the above questions. But the first step is to understand what your operational policies are across your production or test-development environments and getting the right metrics.

I take a simplistic example over the summer, my 7 year old son fell in love with playing his Ninjago game he played for 30-45 minutes at a stretch. But now school is on and he is entitled to play for 10 minutes after his homework is done. His demand what he wants is still to play for 30-45 minutes. When he does not get what he wants, there is contention (tantrums!).Virtual Machines ( VMs) in vSphere are very similar to my son! Lets take the example shown below of a SQL VM configured with 16GB capacity.


Some points to note :
- What a VM is configured with is what we call allocation. What a VM demands due its OS/Application workload is Demand. What a VM gets is Usage. What a VM does not get is Contention.
So what a VM wants = what a VM gets + what a VM does not get
Or Demand = Usage + Contention

- If you do sizing or capacity planning based on just usage you may be under-sizing and under planning. If you size or plan future capacity based on allocation, you may be over-sizing or over-provisioning it.

In addition, there are several metrics available in vCenter for different purposes e.g. Memory consumed is a great metric to tell you how ballooning and sharing is working ummm. But wait it does not tell you how much a VM wants or what is its Demand based on all the active pages it touches. vCenter Operations uses the concepts of Allocation, Demand etc to help you analyze the right way.

Ok, so we got the right metrics, now lets understand what are your policies to manage capacity and risk across your production or test-dev environment.

Several customers wantto optimize for performance in production environment but optimize for higher density of VMs in their test-dev environment.

They over-commit CPU and Memory in test-dev but dont over-commit in production. They have higher buffers in production etc. vCenter operations enables you to capture your operational knobs into policies used by its analytics. It also provides out of box policies such as production and test-dev that can be used.

Dont forget to check out our part 2 of this Tech Tip series on getting the right visuals to understand demand, utilization and capacity risk in your virtual environment!

VMware Virtualization Management Blog: vCenter Operations Management Tech Tips: Tip #9 – Best Practices for vSphere Capacity Planning – Part 1 of 4

Welcome back from VMworld San Francisco 2013. We promised that we will come back and share the content from our VMworld presentations on vSphere Capacity Planning using vCenter Operations. Here is a mini-series of Tech Tips  covering:

1) picking the right metrics and knowing your operational knobs
2) picking the right visuals to understand
2a) your VM growth, Infrastructure burn rate and capacity risk
2b) how to optimize your infrastructure utilization and realize savings?
2c) determining if you have enough capacity for future growth?

Some of the patterns I am seeing across the infrastructure IT leaders are often around trying to find answers to these key questions for effective capacity planning:

i) Am I meeting my SLAs or do I have capacity risk?
   - by analyzing VM growth, infrastructure burn rate and capacity risk
ii) Can I optimize & improve infrastructure utilization & realize savings?
   - by reclaiming unused resources & increasing utilization safely
iii) Do I have enough for future growth?
   - What does my VM demand growth looks like and do I have enough or will i run out?

Working with several IT leaders, we present here how they are using vCenter Operations to get answers to the above questions. But the first step is to understand what your operational policies are across your production or test-development environments and getting the right metrics.

I take a simplistic example – over the summer, my 7 year old son fell in love with playing his Ninjago game – he played for 30-45 minutes at a stretch. But now school is on and he is ‘entitled’ to play for 10 minutes after his homework is done. His ‘demand’ – what he wants is still to play for 30-45 minutes. When he does not get what he wants, there is ‘contention’ (tantrums!).  Virtual Machines ( VMs) in vSphere are very similar to my son! Lets take the example shown below of a SQL VM configured with 16GB capacity.


Some points to note :
- What a VM is configured with is what we call ‘allocation’. What a VM demands due its OS/Application workload is ‘Demand’. What a VM gets is ‘Usage’. What a VM does not get is ‘Contention’.
So what a VM wants  = what a VM gets + what a VM does not get
Or Demand = Usage + Contention

 - If you do sizing or capacity planning based on just ‘usage’ you may be under-sizing and under planning. If you size or plan future capacity based on allocation, you may be over-sizing or over-provisioning it.

In addition, there are several metrics available in vCenter  – for different purposes – e.g. Memory consumed is a great metric to tell you how ballooning and sharing is working  – ummm. But wait it  does not tell you how much a VM wants – or what is its Demand – based on all the active pages it touches. vCenter Operations uses the concepts of Allocation, Demand etc to help you analyze the right way.

Ok, so we got the right metrics, now lets understand what are your policies to manage capacity and risk across your production or test-dev environment.

Several customers want to optimize for performance in production environment but optimize for higher density of VMs in their test-dev environment.

They over-commit CPU and Memory in test-dev but don’t over-commit in production. They have higher buffers in production etc. vCenter operations enables you to capture your ‘operational knobs’ into policies used by its analytics. It also provides out of box policies such as ‘production’ and ‘test-dev’ that can be used.

Don’t forget to check out our part 2 of this Tech Tip series on getting the right visuals to understand demand, utilization and capacity risk in your virtual environment!

Posted in Uncategorized

VMware Support Insider: Using VisualEsxtop to troubleshoot performance issues in vSphere

What is VisualEsxtop?

VisualEsxtop is a new performance monitoring tool that was recently posted on the VMware Labs Flings project. On Flings, apps and tools built by VMware engineers for fun are available for download. The intent is to make VMware Administrators’ lives easier in their daily work.

Note:  VisualEsxtop is not an official VMware tool. For support and feedback please contact VMware Labs : http://labs.vmware.com/contact-us

VisualEsxtop is an enhanced version of resxtop and esxtop. VisualEsxtop can connect to VMware vCenter Server or ESX hosts, and display ESX server stats with a better user interface and more advanced features.

How to install VisualEsxtop ?

  1. Download visualEsxtop.zip from http://labs.vmware.com/flings/visualesxtop
  2. Unzip visualEsxtop.zip to folder
  3. Make sure Java 1.6 is in the PATH.
    1. On windows, to verify if Java is in the path,
      Click on Start > run > TYPE cmd and press ENTER > TYPE java and press Enter.
      If java is not in path, you will notice error like this -
    2. If JDK 1.6 or later is already installed on your machine but not in the path, here is how you add it (Instructions for Windows 7, other versions might be slightly different)
      -Go to Control Panel > System and Security > System >
      -Click Advanced system settings
      -Click on Environmental Variables
      -Click on New
      -Under Edit User Variable type the following and click OK
      Variable name: path
      Variable value: The path to the JDK 1.6 binary folder (C:Program Files (x86)Javajdk1.6.0_14bin  for example)
    3. Then, open cmd again (Start > Run> Type cmd) and type “java”. This should successfully return usage options for java command.

What can you do with VisualEsxtop?

  • Real-time Performance monitoring of individual ESX(i) hosts or vCenter Server. The default interval (5 seconds) is modifiable. Type Ctrl+N and change to the new value
  • Multiple sessions to different hosts or same host at the same time. This comes in very handy when you are comparing stats between hosts or between multiple views/fields.
  • Flexible counter selection and filtering. This is in my opinion the best feature of this tool. You can filter results to get specific outputs. The examples in the next section will show you how to.
  • Save data to a batch file. You can now pick and choose relevant tabs and fields and also chose intervals, number of snapshots for the output. Type Ctrl+S to get the save option
  • Load batch output and replay them. Type Ctrl+B to load a saved csv file.
  • Line chart for selected performance counters
  • Embedded tooltip for counter description
  • Color coding for important counters

Running the tool:

  1. Run visualEsxtop.sh (Linux) or visualEsxtop.bat (Windows) from the extracted files.  (Note: Type export JAVA_OPTS=-Xmx2048m  if loading large amounts of data)
  2. On the VMWARE VisualEsxtop window, select File > Connect to Live server.
  3. Choose the IP address of the host or vCenter and the credentials to connect.

Examples of using the tool:

Example 1:

The example below is listing only the devices that have DAVG value of above 20ms. The filter used is DAVG/cmd under Disk World tab.  Typically we do not want DAVG (device driver level  latency) to be over 20ms for lengthy period. Note that by using the filter, it is very easy to list only the devices that currently have high latency values.

Example 2:

The example below is listing the vmkernels and virtual machines that are currently running on vmnic0. The filter used is TEAM-PNIC  under Network tab. You can also sort by %DRPTX , %DRPRX to filter for any devices reporting packet drops. Note that the vmnic number will only show up if the uplink ports are not in an etherchannel binding.

Tips on working with Charts:

  • To build a new chart, under Chart tab click twice on Object Types to start to select fields
  • To add a field to the chart, expand the related object and click twice on the field
  • To remove a field from the current chart, click twice on the field from the bottom left window pane
  • The chart allows you to add any fields from any objects at the same time. You have to be the judge regarding what fields are relevant. For example, listing DAVG and Physical CPU Core Util% in the same chart may not provide much value.

Chart view (tab) screenshot:

Where do I get tips on Troubleshooting performance on ESXi ?

Details about different fields in esxtop tool can be found in this communities blog post: Interpreting esxtop Statistics.

There are many great articles and tips on performance troubleshooting in the VMware Knowledgebase. Here are a couple that I recommend to give you a start –

VMware Support Insider: Using VisualEsxtop to troubleshoot performance issues in vSphere

What is VisualEsxtop?

VisualEsxtopis a new performance monitoring tool that was recently posted on the VMware Labs Flings project. On Flings, apps and tools built by VMware engineers for fun are available for download. The intent is to make VMware Administrators lives easier in their daily work.

Note: VisualEsxtop is not an official VMware tool. For support and feedback please contact VMware Labs : http://labs.vmware.com/contact-us

VisualEsxtop is an enhanced version of resxtop and esxtop. VisualEsxtop can connect to VMware vCenter Server or ESX hosts, and display ESX server stats with a better user interface and more advanced features.

How to install VisualEsxtop ?

  1. Download visualEsxtop.zip from http://labs.vmware.com/flings/visualesxtop
  2. Unzip visualEsxtop.zip to folder
  3. Make sure Java 1.6 is in the PATH.
    1. On windows, to verify if Java is in the path,
      Click on Start > run > TYPE cmd and press ENTER > TYPE java and press Enter.
      If java is not in path, you will notice error like this -
    2. If JDK 1.6 or later is already installed on your machine but not in the path, here is how you add it (Instructions for Windows 7, other versions might be slightly different)
      -Go to Control Panel > System and Security > System >
      -Click Advanced system settings
      -Click on Environmental Variables
      -Click on New
      -Under Edit User Variable type the following and click OK
      Variable name: path
      Variable value:The path to the JDK 1.6 binary folder (C:Program Files (x86)Javajdk1.6.0_14bin for example)
    3. Then, open cmd again (Start > Run> Type cmd) and type java. This should successfully return usage options for java command.

What can you do with VisualEsxtop?

  • Real-time Performance monitoring of individual ESX(i) hosts or vCenter Server. The default interval (5 seconds) is modifiable. Type Ctrl+N and change to the new value
  • Multiple sessions to different hosts or same host at the same time. This comes in very handy when you are comparing stats between hosts or between multiple views/fields.
  • Flexible counter selection and filtering. This is in my opinion the best feature of this tool. You can filter results to get specific outputs. The examples in the next section will show you how to.
  • Save data to a batch file. You can now pick and choose relevant tabs and fields and also chose intervals, number of snapshots for the output. Type Ctrl+S to get the save option
  • Load batch output and replay them. Type Ctrl+B to load a saved csv file.
  • Line chart for selected performance counters
  • Embedded tooltip for counter description
  • Color coding for important counters

Running the tool:

  1. Run visualEsxtop.sh (Linux) or visualEsxtop.bat (Windows) from the extracted files. (Note: Typeexport JAVA_OPTS=-Xmx2048mif loading large amounts of data)
  2. On the VMWARE VisualEsxtop window, select File > Connect to Live server.
  3. Choose the IP address of the host or vCenter and the credentials to connect.

Examples of using the tool:

Example 1:

The example below is listing only the devices that have DAVG value of above 20ms. The filter used is DAVG/cmd under Disk World tab. Typically we do not want DAVG (device driver level latency) to be over 20ms for lengthy period. Note that by using the filter, it is very easy to list only the devices that currently have high latency values.

Example 2:

The example below is listing the vmkernels and virtual machines that are currently running on vmnic0. The filter used is TEAM-PNIC under Network tab. You can also sort by %DRPTX , %DRPRX to filter for any devices reporting packet drops. Note that the vmnic number will only show up if the uplink ports are not in an etherchannel binding.

Tips on working with Charts:

  • To build a new chart, under Chart tab click twice on Object Types to start to select fields
  • To add a field to the chart, expand the related object and click twice on the field
  • To remove a field from the current chart, click twice on the field from the bottom left window pane
  • The chart allows you to add any fields from any objects at the same time. You have to be the judge regarding what fields are relevant. For example, listing DAVG and Physical CPU Core Util% in the same chart may not provide much value.

Chart view (tab) screenshot:

Where do I get tips on Troubleshooting performance on ESXi ?

Details about different fields in esxtop tool can be found in this communities blog post: Interpreting esxtop Statistics.

There are many great articles and tips on performance troubleshooting in the VMware Knowledgebase. Here are a couple that I recommend to give you a start

VROOM!: Simulating different VDI users with View Planner 3.0

VDI benchmarking is hard. What makes it challenging is getting a good representation or simulation of VDI users. If we closely look at typical office users, we can get a spectrum of VDI users where at the one end of spectrum, the user may be using some simple Microsoft Office applications at a relatively moderate speed, whereas at the other end of spectrum, the user may be running some CPU-heavy multimedia applications and switching between many applications much faster. We classify the fast user as the power user or the heavy user, whereas we classify the user at the other end of the spectrum as the task worker or as the light user. In between the two categories, we define one more category which lies in between these two ends of the spectrum, which is the medium user.

To simulate these different categories of users and to make the job of VDI benchmarking much easier, we have made VMware View Planner 3.0, which simulates a workload representative of many user-initiated operations that take place in a typical VDI environment. The tool simulates typical Office user applications such as PowerPoint, Outlook, and Word; and Adobe Reader, Internet Explorer Web browser, multimedia applications, and so on. The tool can be downloaded from:http://www.vmware.com/products/desktop_virtualization/view-planner/overview.html.

If we look at the three categories of VDI users outlined above, one of the main differentiating factors across this gamut of VDI users is how fast they act and this is simulated using the concept of think time in the View Planner tool. The tool uses thethinktimeparameter to randomly sleep before starting the next application operation. For the heavy user, the value of thinktime is kept very low at 2 seconds. This means that operations are happening very fast and users are switching across different applications or doing operations in an application every 2 seconds on average. The View Planner 3.0 benchmark defines a score, called VDImark which is based on this heavy user workload profile. For a medium user, the think time is set to 5 seconds, and for a light user, the think time is set to 10 seconds. The heavy VDI user also uses a bigger screen resolution compared to the medium or light user. The simulation of these category of users in the View Planner tool is summarized in the table below:

In order to show the capability of View Planner 3.0 to determine the sizing for VDI user VMs per host, we ran a flexible mode of View Planner 3.0, which allowed us to create medium and light user workloads (the heavy workload profile pre-exists), as well to understand the user density for different types of VDI users for a given system. The flexible mode will be available soon through Professional Services Organization (PSO) and to selected partners.

The experimental setup we used to compare these different user profiles is shown below:

In this test, we want to determine how many VMs can be run on the system while each VM is performing its heavy, medium, or light user profiles. In order to do this, we need to set a baseline of acceptable performance, which is defined by the quality of service (QoS) as defined in the View Planner user guide. The number of VMs that passed the QoS score is shown in the chart below.

The chart shows that we can run about 53 VMs for the heavy user (VDImark), 67 VMs for the medium user, and 91 VMs for light users. So, we could consolidate about 25% more desktops if we used this system to host users with medium workloads instead of heavy workloads. And we could consolidate 35% more desktops if we used this system to host users with light workloads instead of medium workloads.So, it is crucial to fully specify the user profile whenever we talk about the user density.

In this blog, we demonstrated how we used the View Planner 3.0 flexible mode to run different user profiles and to understand the user density fora system under test. If you have any questions and want to know more about View Planner, you can reach out to the team at viewplanner-info@vmware.com