Personal vDisk – VM Test

The personal vDisk retains the single image management of pooled and streamed desktops while allowing people to install applications and change their desktop settings.

Unlike traditional Virtual Desktop Infrastructure (VDI) deployments involving pooled desktops, where users lose their customizations and personal applications when the administrator alters the base virtual machine (VM), deployments using personal vDisks retain those changes. This means administrators can easily and centrally manage their base VMs while providing users with a customized and personalized desktop experience.

Personal vDisks provide this separation by redirecting all changes made on the user’s VM to a separate disk (the personal vDisk) attached to the user’s VM. The content of the personal vDisk is blended at runtime with the content from the base VM to provide a unified experience. In this way, users can still access applications provisioned by their administrator in the base VM.

But, what happens if a personal vDisk runs out of space? Simple! Users will no longer be able to hold on to their customizations, allowing them access to only the base VM and the applications installed therein! This outcome beats the entire purpose of having personal vDisks! If this is to be avoided, then administrators should continuously monitor the usage of the personal vDisks, proactively detect a potential space crunch, determine what is causing the rapid erosion of space on the personal vDisk, and fix the root-cause, before desktop users complain. This is where the Personal vDisk – VM test helps.

For each VM on a Nutanix Acropolis server, this test tracks the status and space usage of its personal vDisk and promptly reports errors / abnormal space usage. This way, administrators can accurately identify personal vDisks with very limited space, which VM such personal vDisks are associated with, and what is consuming too much disk space – user profiles? Or user applications?

Target of the test : A Nutanix Acropolis server

Agent deploying the test : A remote agent

Outputs of the test : One set of results for every user_on_VM.

Configurable parameters for the test

  1. Test period - How often should the test be executed
  2. Host - The host for which the test is to be configured.
  3. port - The port at which the specified host listens. By default, this is NULL.
  4. Prism IP - If the eG manager had discovered the target Nutanix Acropolis server by connecting to the Nutanix Prism, then the IP address of the Nutanix Prism server used for discovering this Nutanix Acropolis server would be automatically displayed against the prism ip parameter; similarly, the prism user and prism password text boxes will be automatically populated with the Prism user credentials, using which Nutanix Acropolis discovery was performed.

     

    If this Nutanix Acropolis server has not been discovered using the Nutanix Prism, but you still want to monitor the Nutanix Acropolis server via the Prism, then select the IP address of the Prism server that you wish to use for monitoring the Nutanix Acropolis server from the prism ip list. By default, this list is populated with the IP address of all Nutanix Prism hosts that were added to the eG Enterprise system at the time of discovery. Upon selection, the PRISM user and prism password that were pre-configured for that vCenter server will be automatically displayed against the respective text boxes.

     

    On the other hand, if the IP address of the Prism server of interest to you is not available in the list, then, you can add the details of the Prism server on-the-fly, by selecting the Other option from the prism ip list. This will invoke the MANAGER DISCOVERY - VIRTUAL PLATFORM SETTINGS page. Refer to the Configuring eG Enterprise to Monitor Nutanix Acropolis topic for details on how to use this page.

  5. Prism user and prism password - If the eG manager had discovered the target Nutanix Acropolis server by connecting to the Nutanix Prism, then the IP address of the Nutanix Prism server used for discovering this Nutanix Acropolis server would be automatically displayed against the prism ip parameter; similarly, the prism user and prism password text boxes will be automatically populated with the Prism user credentials, using which Nutanix Acropolis discovery was performed.

     

    If this Nutanix Acropolis server has not been discovered using the Nutanix Prism, but you still want to monitor the Nutanix Acropolis server via the Prism, then select the IP address of the Prism server that you wish to use for monitoring the Nutanix Acropolis server from the prism ip list. By default, this list is populated with the IP address of all Nutanix Prism hosts that were added to the eG Enterprise system at the time of discovery. Upon selection, the PRISM user and prism password that were pre-configured for that Nutanix Prism will be automatically displayed against the respective text boxes.

    On the other hand, if the IP address of the Prism server of interest to you is not available in the list, then, you can add the details of the Prism server on-the-fly, by selecting the Other option from the prism ip list. This will invoke the MANAGER DISCOVERY - VIRTUAL PLATFORM SETTINGS page. Refer to the Configuring eG Enterprise to Monitor Nutanix Acropolis topic for details on how to use this page.

  6. confirm password - Confirm the password by retyping it here.
  7. ssl - By default, the Nutanix Prism server is SSL-enabled. Accordingly, the SSL flag is set to Yes by default. This indicates that the eG agent will communicate with the Prism server via HTTPS by default.

  8. webport - By default, the Nutanix Prism server listens on port 9440. This implies that while monitoring a Nutanix Acropolis server via the Prism server, the eG agent connects to port 9440.

  9. exclude vms - Administrators of some virtualized environments may not want to monitor some of their less-critical VMs both from ‘outside’ and from ‘inside’. The eG agent in this case can be configured to completely exclude such VMs from its monitoring purview. To achieve this, provide a comma-separated list of VMs to be excluded from monitoring in the exclude vms text box. Instead of VMs, VM name patterns can also be provided here in a comma-separated list. For example, your exclude vms specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside and outside views of all VMs on a virtual host by default. By providing a comma-separated list of VMs/VM name patterns in the exclude vms text box, you can make sure the eG agent stops collecting ‘inside’ and ‘outside’ view metrics for a configured set of VMs.
  10. ignore vms inside view - Administrators of some high security Nutanixe environments might not have permissions to internally monitor one/more VMs. The eG agent can be configured to not obtain the inside view of such ‘inaccessible’ VMs using the ignore vms inside view parameter. Against this parameter, you can provide a comma-separated list of VM names, or VM name patterns, for which the inside view need not be obtained. For instance, your ignore vms inside view specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside view of all VMs on a Nutanix Acropolis server by default.

    Note:

    While performing VM discovery, the eG agent will not discover the operating system of the VMs configured in the ignore vms inside view text box.

  11. ignore winnt - By default, the eG agent does not support the inside view for VMs executing on Windows NT operating systems. Accordingly, the ignore winnt flag is set to Yes by default.
  12. inside view using - By default, this test communicates with every VM remotely and extracts “inside view” metrics. Therefore, by default, the inside view using flag is set to Remote connection to VM (Windows).

    Typically, to establish this remote connection with Windows VMs in particular, eG Enterprise requires that the eG agent be configured with domain administrator privileges. In high-security environments, where the IT staff might have reservations about exposing the credentials of their domain administrators, this approach to extracting “inside view” metrics might not be preferred. In such environments therefore, eG Enterprise provides administrators the option to deploy a piece of software called the eG VM Agent (Windows) on every Windows VM; this VM agent allows the eG agent to collect “inside view” metrics from the Windows VMs without domain administrator rights. Refer to Configuring the eG Agent to Collect Current Hardware Status Metrics for more details on the eG VM Agent. To ensure that the “inside view” of Windows VMs is obtained using the eG VM Agent, set the inside view using flag to eG VM Agent (Windows). Once this is done, you can set the domain, admin user, and admin password parameters to none.

  13. domain, admin user, admin password, and confirm password - By default, this test connects to each virtual guest remotely and attempts to collect “inside view” metrics. In order to obtain a remote connection, the test must be configured with user privileges that allow remote communication with the virtual guests. The first step towards this is to specify the DOMAIN within which the virtual guests reside. The admin user and admin password will change according to the domain specification. Discussed below are the different values that the domain parameter can take, and how they impact the admin user and admin password specifications:

    • If the VMs belong to a single domainIf the guests belong to a specific domain, then specify the name of that domain against the domain parameter. In this case, any administrative user in that domain will have remote access to all the virtual guests. Therefore, an administrator account in the given domain can be provided in the ADMIN USER field and the corresponding password in the ADMIN PASSWORD field. Confirm the password by retyping it in the CONFIRM PASSWORD text box.
    • If the guests do not belong to any domain (as in the case of Linux/Solaris guests) :  In this case, specify “none” in the DOMAIN field, and specify a local administrator account name in the ADMIN USER below.

      Prior to this, you need to ensure that the same local administrator account is available or is explicitly created on each of the virtual machines to be monitored. Then, proceed to provide the password of the ADMIN USER against ADMIN PASSWORD, and confirm the password by retyping it in the CONFIRM PASSWORD text box.

      If key-based authentication is implemented between the eG agent and the SSH daemon of a Linux guest, then, in the admin user text box, enter the name of the user whose <user_home_dir> (on that Linux guest) contains a .ssh directory with the public key file named authorized_keys. The admin password in this case will be the passphrase of the public key; the default public key file that is bundled with the eG agent takes the password eginnovations. Specify this as the admin password if you are using the default private/public key pair that is bundled with the eG agent to implement key-based authentication. On the other hand, if you are generating a new public/private key pair for this purpose, then use the passphrase that you provide while generating the pair. For the detailed procedure on Implementing Key-based Authentication refer to Troubleshooting the Failure of the eG Remote Agent to Connect to or Report Measures for Linux Guests.

    • If the guests belong to different domains - In this case, you might want to provide multiple domain names. If this is done, then, to access the guests in every configured domain, the test should be configured with the required user privileges; this implies that along with multiple DOMAIN names, multiple ADMIN USER names and ADMIN PASSWORDs would also have to be provided. To help administrators provide these user details quickly and easily, the eG administrative interface embeds a special configuration page. To access this page, simply click on the Click here hyperlink that appears just above the parameters of this test in the test configuration page. To know how to use the special page, refer to Personal vDisk – VM Test.
    • If the inside view using flag is set to ‘eG VM Agent (Windows)’ - In this case, the inside view can be obtained without domain administrator privileges. Therefore, set the domain, admin user, and admin password parameters to none.
  14. REPORT BY USER - While monitoring a Nutanix Acropolis server, the REPORT BY USER flag is set to No by default, indicating that by default, the guest operating systems on the Acropolis server are identified using the hostname specified in the operating system. On the other hand, while monitoring Acropolis desktop environments, this flag is set to Yes by default; this implies that in case of VDI servers, by default, the guests will be identified using the login of the user who is accessing the guest OS. In other words, in VDI environments, this test will, by default, report measures for every username_on_virtualmachinename.
  15. REPORT POWERED OS - This flag becomes relevant only if thereport by user flagis set to ‘Yes’.

    If the report powered os flag is set to Yes (which is the default setting), then this test will report measures for even those VMs that do not have any users logged in currently. Such guests will be identified by their virtualmachine name and not by the username_on_virtualmachinename. On the other hand, if the report powered os flag is set to No, then this test will not report measures for those VMs to which no users are logged in currently.      

  16. DD FREQUENCY - Refers to the frequency with which detailed diagnosis measures are to be generated for this test. For a Nutanix Acropolis server, this is set to 1:1 by default. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem.

  17. DETAILED DIAGNOSIS - To make diagnosis more efficient and accurate, the eG suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

    The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

    • The eG manager license should allow the detailed diagnosis capability
    • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.

 

Measurements made by the test

Measurement Description Measurement Unit Interpretation

Personal vDisk service status:

Indicates whether Citrix Personal vDisk service is running or not on this VM.

 

The values that this measure can report and their corresponding numeric values have been discussed in the table below:

Measure Value Numeric Value

Stopped

0

Running

1

Not installed

2

Note:

By default, this test reports the Measures Values listed in the table above to indicate the status of the Personal vDisk service. In the graph of this measure however, the same will be represented using the numeric equivalents.

Recompose status:

Indicates the status of the initially provisioned disk or the updated image.

Number

Use the detailed diagnosis of this measure to know for which VM the initial personal vDisk provisioning or image update were unsuccessful and why. The VM can be in one of the following states:

  • OK – The initial provisioning or last image update was successful.
  • Disk Init – This is the first time that the personal vDisk has started or been resized. It is being initialized and partitioned by the service.
  • Disk Format – The personal vDisk is being formatted.
  • Updating – The initial provisioning or an image update is in progress.
  • Error (Disk Discovery) – An error state. An error occurred while discovering the personal vDisk.
  • Error (Disk Init) – An error state. An error occurred while partitioning or formatting the personal vDisk.
  • Error (Sys Init) – An error state. An error occurred while starting the Personal vDisk Service or configuring the personal vDisk.
  • Error (Update) – An error state. An error occurred during the initial provisioning or the last image update.
  • Unknown – An error state. An error occurred but the cause is unknown.

Space used by user applications:

Indicates the amount of space used by applications installed on the personal vDisk attached to this VM.

MB

Personal vDisks have two parts, which use different drive letters and are by default equally sized. 

One part comprises a Virtual Hard Disk file (a .vhd file). This contains items such as applications installed in C:\Program Files. By default, this part uses drive V: but is hidden from users.

These measures indicate how much space has been allocated to this .vhd file and how much of the allocated space has been utilized by user applications contained in this file.

A high value for the Space used by user applications and Space utilized by user applications measures is indicative of excessive space used by user applications. You can compare the value of these measures across VMs to know which user to which VM has utilized too much space reserved for user applications on the personal vDisk. If the value of the Space utilized by user applications measure grows close to 100% for any VM, it implies that potentially, the user to that VM will not be able to install any applications on the personal vDisk; nor access any applications.

Space allocated for user applications:

Indicates the amount of space allocation for storing user applications on the personal vDisk attached to this VM.

MB

Space utilized by user applications:

Indicates the percentage of allocated space used by applications installed on the personal vDisk attached to this VM.

Percent

Space used by user profiles:

Indicates the amount of space used for storing user profiles on the personal vDisk attached to this VM.

MB

Personal vDisks have two parts, which use different drive letters and are by default equally sized. 

One part comprises C:\Users (in Windows 7) or C:\Documents and Settings (in Windows XP). This contains user data, documents, and the user profile. By default this uses drive P:.

These measures indicate how much space has been allocated to user profiles and how much of the allocated space has been utilized by user profiles.

A high value for the Space used by user profiles and Space utilized by user profiles measures is indicative of excessive space used by user profiles. You can compare the value of these measures across VMs to know which VM’s user profiles are consuming the maximum space on the personal vDisk. If the value of the Space utilized by user profiles measure grows close to 100% for any VM, it implies that potentially, the user to that VM will not be able to store/access any more documents or user data on the personal vDisk .

Space allocated for user profiles:

Indicates the amount of space allocated for storing user profiles on the personal vDisk attached to this VM.

MB

Space utilized by user profiles:

Indicates the percentage of allocated space that has been used up by user profiles on the personal vDisk attached to this VM.

Percent

Free space:

Indicates the amount of unused space on the personal vDisk attached to this VM.

MB

Ideally, the value of this measure should be high. You can compare the value of this measure across VMs to know which VM’s personal vDisk has the least free space. You may then want to resize that personal vDisk to accommodate more data.

Total size:

Indicates the total size of the personal vDisk attached to this VM.

MB

The minimum size of a Personal vDisk is 3 GB, however a size of 10 GB is recommended.

Space utilized:

Indicates the percentage of space in the personal vDisk attached to this VM that is currently used.

Percent

A consistent increase in the value of this measure is a cause for concern, as it indicates a gradual erosion of free space in the personal vDisk of a VM.

By comparing the value of this measure across VMs, you can identify which VM’s personal vDisk is running out of space! Once the VM with the space-hungry vDisk is isolated, you may want to compare the value of the Space utilized by user applications and Space utilized by user profiles measures of that VM, to clearly understand what is occupying too much space in the personal vDisk – is it the user profiles? Or is it the user applications? Based on this inference, you can figure out which drive partition of the personal vDisk has limited free space, and can decide between freeing up space in that partition or allocating more space to the personal vDisk itself.