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limbo

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Limbo

Most new information will end up here, until it matures and finds a proper home.

Nas4Free

ZFS Cleanup Command

Delete num of the oldest snapshots, filtered by filt:

zfs list -t snapshot -o name -S creation | grep filt | tail -n +num | xargs -n 1 zfs destroy -r

Operating System Deployment

Image Capture

Via DISM from WinPE

  • c: drive is the operating system we are capturing (may not always be c:)
  • z: drive is the target location where we're saving the image
  • Recommend naming the WIM file [VM_name]-[Description].wim
  • Recommend the /name switch be [Windows Edition] - [Description] build
  • If the /compress switch is omitted then the default compression of fast will be used
dism /capture-image /imagefile:z:\Win10Ent_x64-Custom.wim /capturedir:c:\ /name:"Windows 10 Enterprise - Custom build" /compress:maximum

Misc

WMI

:: query the machine's model
wmic csproduct get name
:: sample output...
Name
Latitude E7250

Applying above information we can filter the Inject Drivers tasks in MDT via the following Query WMI condition:

SELECT * FROM Win32_ComputerSystem WHERE Model LIKE "%Latitude%7250%"

CMD

PowerShell

GUIDs

Script to generate N GUIDs

[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') | Out-Null
$count = [Microsoft.VisualBasic.Interaction]::InputBox("How many GUIDs to generate?", "Question", 1)
 
$file = ".\GUIDs.txt"
Remove-Item $file -Force -ErrorAction Ignore
 
$guids = @()
 
for($i=0; $i -lt $count; $i++){
    $guids += New-Guid
}
 
$guids | ConvertTo-Csv -NoTypeInformation | select -Skip 1 | % {$_ -replace '"', ""} | Out-File $file -Encoding utf8

XML

Saving with XmlWriter for more control

# this is our file with XML data
$fileName = "c:\stuff\data.xml"
 
# get content from the file and cast it as XML
[xml]$data = get-content $fileName
 
# do stuff with the XML
 
# back-up the old file just in case
Copy-Item $fileName ($fileName + ".bak")
 
# save the standard way
# $data.Save($fileName)
# ^ this works in most cases, but we have no control over the file encoding, nor the formatting of the XML
# so we are likely to just get condensed XML without any white-space formatting
 
# save the fun way
# first we use XmlWriterSettings to set the text encoding and indent formatting
$xmlSettings = New-Object System.Xml.XmlWriterSettings
$xmlSettings.Encoding = [System.Text.Encoding]::ASCII
$xmlSettings.Indent = $true
# then we use the XmlWriter to save
$xmlWriter = [System.XML.XmlWriter]::Create($fileName, $xmlSettings)
$data.Save($xmlWriter)
# remember to flush and close the XmlWriter
$xmlWriter.Flush()
$xmlWriter.Close()

GPO

Scheduled Tasks as SYSTEM

In many cases it is desirable to run Scheduled Tasks as NT AUTHORITY\SYSTEM, however the wizard occasionally messes this up for us after clicking OK. This is visible when re-opening the Scheduled Task and reviewing its settings. The easiest solution is to go in to the XML and replace the relevant bit.

For example, here is an entire ScheduledTasks.xml that will run a PowerShell script on three triggers - machine startup, 8am, and 5pm. It allows running on-demand, and will run asap after missed schedule. The preference item is also going to get removed when the GPO is no longer applied, so the preference item is setup as Replace.

<?xml version="1.0" encoding="utf-8"?>
<ScheduledTasks clsid="{SOME-GUID-0}">
    <TaskV2 clsid="{SOME-GUID-1}" name="Task Name" image="1" changed="2018-05-24 18:21:33" uid="{SOME-GUID-2}" disabled="0" userContext="0" removePolicy="1">
        <Properties action="R" name="Task Name" runAs="NT AUTHORITY\SYSTEM" logonType="Group">
            <Task version="1.3">
                <RegistrationInfo>
                    <Author>domain\some-sysadmin</Author>
                    <Description></Description>
                </RegistrationInfo>
                <!-- START OF THE IMPORTANT PART -->
                <Principals>
                    <Principal id="Author">
                        <RunLevel>HighestAvailable</RunLevel>
                        <GroupId>NT AUTHORITY\SYSTEM</GroupId>
                    </Principal>
                </Principals>
                <!-- END OF THE IMPORTANT PART -->
                <Settings>
                    <IdleSettings>
                        <Duration>PT5M</Duration>
                        <WaitTimeout>PT1H</WaitTimeout>
                        <StopOnIdleEnd>false</StopOnIdleEnd>
                        <RestartOnIdle>false</RestartOnIdle>
                    </IdleSettings>
                    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
                    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
                    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
                    <AllowHardTerminate>false</AllowHardTerminate>
                    <AllowStartOnDemand>true</AllowStartOnDemand>
                    <Enabled>true</Enabled>
                    <Hidden>false</Hidden>
                    <ExecutionTimeLimit>PT0S</ExecutionTimeLimit>
                    <Priority>7</Priority>
                    <StartWhenAvailable>true</StartWhenAvailable>
                    <RunOnlyIfNetworkAvailable>true</RunOnlyIfNetworkAvailable>
                </Settings>
                <Triggers>
                    <BootTrigger>
                        <Enabled>true</Enabled>
                    </BootTrigger>
                    <CalendarTrigger>
                        <StartBoundary>2018-04-26T08:00:00</StartBoundary>
                        <Enabled>true</Enabled>
                        <ScheduleByDay>
                            <DaysInterval>1</DaysInterval>
                        </ScheduleByDay>
                    </CalendarTrigger>
                    <CalendarTrigger>
                        <StartBoundary>2018-04-26T17:00:00</StartBoundary>
                        <Enabled>true</Enabled>
                        <ScheduleByDay>
                            <DaysInterval>1</DaysInterval>
                        </ScheduleByDay>
                    </CalendarTrigger>
                </Triggers>
                <Actions Context="Author">
                    <Exec>
                        <Command>powershell.exe</Command>
                        <Arguments>-ExecutionPolicy Bypass -File "\\path-to-script\script.ps1" -Parameter "stuff"</Arguments>
                    </Exec>
                </Actions>
            </Task>
        </Properties>
    </TaskV2>
</ScheduledTasks>
limbo.1527856042.txt.gz · Last modified: 2018/06/01 08:27 by thekojukinator