Getting convert VHD jobs per VM from SCVMM 2012

I have been running some tests recently and one of the things that was brought into question is if a disk conversion job is taking longer to run as the number of VMs increases in the environment.

Now, you might think this is relatively easy.  Just issue a query with Get-SCJob and filter.

Well, I did begin that way, thinking I would get just what I wanted.

Get-SCJob | where { $_.Name -eq "convert virtual hard disk" } | where { $_.Status -eq "Completed" }

But I never got the right number of VHD conversion jobs returned back.  This obviously needed more complex scripting.

So, I tried using Get-SCVirtualDiskDrive   That cmdlet requires a VM object to be tossed in, I can’t just get a list of all the VHD like I could through a CIM call to a hypervisor.

Now I have to go to the VM level.  I have to query for the VMs, then find each virtual disk, then get the most recent job object on that virtual disk.

$scVMs = Get-SCVirtualMachine | where {$_.Name -match "Xd1K"}

In a long hand way that looks like this:

Foreach ($scVM in $scVMs){
    $vmVhd = Get-SCVirtualDiskDrive -VM $scVM | where {$_.MostRecentTask -match "convert"} 
    $vhdJob = $vmVhd.MostRecentTask
    $vhdConvertJobs += [Microsoft.SystemCenter.VirtualMachineManager.Task]$vhdJob
}

Take notice of that object cast; [Microsoft.SystemCenter.VirtualMachineManager.Task].  If you don’t do this you get an error that the Task cannot be converted to int32.  Don’t ask me why PowerShell is trying to convert the Task object into an integer, but that is what the default is trying to do.

In a nice tight shorthand way it looks like this:

Foreach ($scVM in $scVMs){
    $vhdConvertJobs += [Microsoft.SystemCenter.VirtualMachineManager.Task]( Get-SCVirtualDiskDrive -VM $scVM | where {$_.MostRecentTask -match "convert"} ).MostRecentTask
}

Next time, calculating the average time to execute the jobs, and making it useful to quickly check.

Traversing time with PowerShell

My first title for this was “the PowerShell time machine” because the article is about TimeSpan and managing time using TimeSpan.

Most folks are familiar with Get-Date.  Get-Date is all about ‘now’ – it is always now. 

Which is great, if you are running a script and want to know at some point in the script what the time is ‘now’, such as before entering a loop of some type.

Frequently I need to calculate the difference between then and now.  Or the difference between then and then.  This is where the TimeSpan comes into play.

My current project involves trudging through entries in a log file and finding a start time for a series of steps, and then the end time for the series of steps.  The whole point is that I need to know how long the series of steps took so that we can see if we made it any faster.

I don’t know about you but I have a hard time with determining the minutes in between 09:54:53 and 14:13:33.  That isn’t something I can look at and do in my head.

This is not the most elegant script and I know it can be improved.  However, this is where I began taking basic keyboard text entry and turning it into time.

If you run the script it asks you for the start time, entering HH, then MM, then SS.  Then the end time, again. HH, then MM, then SS.  Then it calculates the difference.

do {
    Clear-Host
   
    $startTime = New-TimeSpan -Hours (read-host -prompt "Enter Start hour HH") -Minutes (read-host -prompt "Enter Start minutes MM") -Seconds (read-host -prompt "Enter Start seconds SS")

    $endTime = New-TimeSpan -Hours (read-host -prompt "Enter End hour HH") -Minutes (read-host -prompt "Enter End minutes MM") -Seconds (read-host -prompt "Enter End seconds SS")

    $timeToExecute = $endTime - $startTime

    ""
    "   The task took: _" + $timeToExecute.TotalMinutes + "_ minutes"
    ""
   
    $quit = Read-Host -Prompt "press Enter to continue or 00 Enter to quit"
   
    Clear-Variable -Name startTime
    Clear-Variable -Name endTime

   
} until ($quit -eq "00")

psbase.gettext(1) I love you

I have had many cases to do things in PowerShell where I am manipulating CIM or WMI objects.
Getting CIM/WMI objects and querying information from them is never a big deal, however modifying an object and then trying to send it back to a method to cause some setting change has always been a pain.
When you get a CIM/WMI object with PowerShell, PowerShell treats it as an object, where in actuality it is XML.  It is a representation of am object.  It has a path and properties.
Over time I have treated this all kinds of ways to get it to format properly for the receiving CIM/WMI.
You can deal with it as InnerText, you can convert it to XML, you can deal with is as a complex string @” <stuff in there with intact formatting> ”@
When PowerShell sees the WMI as an object you can manipulate it in an easy object type of way.  But you can’t send it back to a WMI method.
When PowerShell sees the CIM as a string, you can manipulate it in a painful way, but you can easily send it back to a CIM method.
As a consumer who uses both Windows CIM (WMI) and Linux CIM (CIM) this is a royal pain.  Especially when PowerShell automatic object handling does not recognize the return properly (which I have had happen with CIM lots of times).  Now, I know that PowerShell 3 (in the Win8 Developer Preview) will make this all much better, but I am not there yet.
Lets just take a quick look at the object and return.
When you perform a query against WMI you get a single object or an array of objects back.  But PowerShell treats them like objects.  You can “.” the properties and methods.  This is powerful.

PS C:\Users\Public\Documents\> $vsmssd

__GENUS                    : 2
__CLASS                    : Msvm_VirtualSystemManagementServiceSettingData
__SUPERCLASS               : CIM_SettingData
__DYNASTY                  : CIM_ManagedElement
__RELPATH                  : Msvm_VirtualSystemManagementServiceSettingData.InstanceID="Microsoft:BJEDAR2"
__PROPERTY_COUNT           : 13
__DERIVATION               : {CIM_SettingData, CIM_ManagedElement}
__SERVER                   : BJEDAR2
__NAMESPACE                : root\virtualization
__PATH                     : \\BJEDAR2\root\virtualization:Msvm_VirtualSystemManagementServiceSettingData.InstanceID="Microsoft:BJEDAR2"
BiosLockString             :
Caption                    : Hyper-V Virtual System Management Service
DefaultExternalDataRoot    : C:\Users\Public\VMs\
DefaultVirtualHardDiskPath : C:\Users\Public\VMs\
Description                : Settings for the Virtual System Management Service
ElementName                : Hyper-V Virtual System Management Service
InstanceID                 : Microsoft:BJEDAR2
MaximumMacAddress          : 00155D748DFF
MinimumMacAddress          : 00155D680A00
NumaSpanningEnabled        : True
PrimaryOwnerContact        :
PrimaryOwnerName           : Administrators
ScopeOfResidence           :

But when I modify that object and send it back to the WMI provider I need to adhere to the CIM standard and I cannot just send back $vsmssd.   That is where this little, wonderful, psbase.gettext method comes into play.  Lets take this object and turn it back into its CIM text so that I can send it back to the WMI provider.
When I type that out to the screen I get something very different, not an object, but useful for sending the message.

PS C:\Users\Public\Documents\> $vsmssd.psbase.gettext(1)
<INSTANCE CLASSNAME="Msvm_VirtualSystemManagementServiceSettingData"><QUALIFIER NAME="dynamic" PROPAGATED="true" TYPE="boolean" TOSUBCLASS="false" TOINSTANCE="true"><VALUE>TRUE</VALU
E></QUALIFIER><PROPERTY NAME="__PATH" CLASSORIGIN="___SYSTEM" TYPE="string"><VALUE>\\BJEDAR2\root\virtualization:Msvm_VirtualSystemManagementServiceSettingData.InstanceID="Microsoft:
BJEDAR2"</VALUE></PROPERTY><PROPERTY NAME="__NAMESPACE" CLASSORIGIN="___SYSTEM" TYPE="string"><VALUE>root\virtualization</VALUE></PROPERTY><PROPERTY NAME="__SERVER" CLASSORIGIN="___S
YSTEM" TYPE="string"><VALUE>BJEDAR2</VALUE></PROPERTY><PROPERTY.ARRAY NAME="__DERIVATION" CLASSORIGIN="___SYSTEM" TYPE="string"><VALUE.ARRAY><VALUE>CIM_SettingData</VALUE><VALUE>CIM_
ManagedElement</VALUE></VALUE.ARRAY></PROPERTY.ARRAY><PROPERTY NAME="__PROPERTY_COUNT" CLASSORIGIN="___SYSTEM" TYPE="sint32"><VALUE>13</VALUE></PROPERTY><PROPERTY NAME="__RELPATH" CL
ASSORIGIN="___SYSTEM" TYPE="string"><VALUE>Msvm_VirtualSystemManagementServiceSettingData.InstanceID="Microsoft:BJEDAR2"</VALUE></PROPERTY><PROPERTY NAME="__DYNASTY" CLASSORIGIN="___
SYSTEM" TYPE="string"><VALUE>CIM_ManagedElement</VALUE></PROPERTY><PROPERTY NAME="__SUPERCLASS" CLASSORIGIN="___SYSTEM" TYPE="string"><VALUE>CIM_SettingData</VALUE></PROPERTY><PROPER
TY NAME="__CLASS" CLASSORIGIN="___SYSTEM" TYPE="string"><VALUE>Msvm_VirtualSystemManagementServiceSettingData</VALUE></PROPERTY><PROPERTY NAME="__GENUS" CLASSORIGIN="___SYSTEM" TYPE=
"sint32"><VALUE>2</VALUE></PROPERTY><PROPERTY NAME="BiosLockString" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="t
rue" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER></PROPERTY><PROPERTY NAME="Caption" CLASSORIGIN="CIM_ManagedElement" TYPE="string"><QUALIFIER NAME="CIMTYPE" PRO
PAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>Hyper-V Virtual System Management Service</VALUE></PROPERTY><PROPERTY NAME="DefaultExternalData
Root" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QU
ALIFIER><VALUE>C:\Users\Public\VMs\</VALUE></PROPERTY><PROPERTY NAME="DefaultVirtualHardDiskPath" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIE
R NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>C:\Users\Public\VMs\</VALUE></PROPERTY><PROPERTY NAME="Description" CLASSOR
IGIN="CIM_ManagedElement" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>Settings for the Virtual S
ystem Management Service</VALUE></PROPERTY><PROPERTY NAME="ElementName" CLASSORIGIN="CIM_ManagedElement" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINS
TANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>Hyper-V Virtual System Management Service</VALUE></PROPERTY><PROPERTY NAME="InstanceID" CLASSORIGIN="CIM_SettingData" TYPE="strin
g"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><QUALIFIER NAME="key" PROPAGATED="true" TYPE="boolean" OVERRIDABLE="fa
lse" TOINSTANCE="true"><VALUE>TRUE</VALUE></QUALIFIER><VALUE>Microsoft:BJEDAR2</VALUE></PROPERTY><PROPERTY NAME="MaximumMacAddress" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSe
ttingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>00155D748DFF</VALUE></PROPERTY><PROPERTY
NAME="MinimumMacAddress" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE
>string</VALUE></QUALIFIER><VALUE>00155D680A00</VALUE></PROPERTY><PROPERTY NAME="NumaSpanningEnabled" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="boolean"><QUA
LIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>boolean</VALUE></QUALIFIER><VALUE>TRUE</VALUE></PROPERTY><PROPERTY NAME="PrimaryOwnerContact" CLASSORIG
IN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>
</VALUE></PROPERTY><PROPERTY NAME="PrimaryOwnerName" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSettingData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="stri
ng" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER><VALUE>Administrators</VALUE></PROPERTY><PROPERTY NAME="ScopeOfResidence" CLASSORIGIN="Msvm_VirtualSystemManagementServiceSetti
ngData" TYPE="string"><QUALIFIER NAME="CIMTYPE" PROPAGATED="true" TYPE="string" TOINSTANCE="true"><VALUE>string</VALUE></QUALIFIER></PROPERTY></INSTANCE>

The actual object is the same thing, in spite of this last looking like a bunch of XML.
If you try to manipulate CIM from a Linux provider with PowerShell you will see lots of this type of output and dealing with it properly is the pain.
Just thought I would share.  Eventually I will get back to Linux CIM interfaces, but I hope I can wait until PowerShell 3 comes out, with handling for CIM, not just WMI.