diff --git a/.vsts-ci/linux-daily.yml b/.vsts-ci/linux-daily.yml
index 6ab1832df..e6a5375b0 100644
--- a/.vsts-ci/linux-daily.yml
+++ b/.vsts-ci/linux-daily.yml
@@ -47,7 +47,7 @@ stages:
   jobs:
   - template: templates/ci-build.yml
     parameters:
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       jobName: linux_build
       displayName: linux Build
 
@@ -56,7 +56,7 @@ stages:
   jobs:
   - job: linux_test
     pool:
-      vmImage: ubuntu-16.04
+      vmImage: ubuntu-20.04
     displayName: Linux Test
 
     steps:
@@ -149,7 +149,7 @@ stages:
   - job: CodeCovTestPackage
     displayName: CodeCoverage and Test Packages
     pool:
-      vmImage: ubuntu-16.04
+      vmImage: ubuntu-20.04
     steps:
     - pwsh: |
         Import-Module .\tools\ci.psm1
diff --git a/.vsts-ci/linux.yml b/.vsts-ci/linux.yml
index bed0c4fd2..0cc592848 100644
--- a/.vsts-ci/linux.yml
+++ b/.vsts-ci/linux.yml
@@ -52,7 +52,7 @@ stages:
   jobs:
   - template: templates/ci-build.yml
     parameters:
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       jobName: linux_build
       displayName: linux Build
 
@@ -62,34 +62,34 @@ stages:
   - template: templates/nix-test.yml
     parameters:
       name: Linux
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       purpose: UnelevatedPesterTests
       tagSet: CI
 
   - template: templates/nix-test.yml
     parameters:
       name: Linux
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       purpose: ElevatedPesterTests
       tagSet: CI
 
   - template: templates/nix-test.yml
     parameters:
       name: Linux
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       purpose: UnelevatedPesterTests
       tagSet: Others
 
   - template: templates/nix-test.yml
     parameters:
       name: Linux
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
       purpose: ElevatedPesterTests
       tagSet: Others
 
   - template: templates/verify-xunit.yml
     parameters:
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
 
 - stage: PackageLinux
   displayName: Package Linux
@@ -97,7 +97,7 @@ stages:
   jobs:
   - template: linux/templates/packaging.yml
     parameters:
-      pool: ubuntu-16.04
+      pool: ubuntu-20.04
 
 - stage: CodeCovTestPackage
   displayName: CodeCoverage and Test Packages
@@ -106,7 +106,7 @@ stages:
   - job: CodeCovTestPackage
     displayName: CodeCoverage and Test Packages
     pool:
-      vmImage: ubuntu-16.04
+      vmImage: ubuntu-20.04
     steps:
     - pwsh: |
         Import-Module .\tools\ci.psm1
diff --git a/.vsts-ci/linux/templates/packaging.yml b/.vsts-ci/linux/templates/packaging.yml
index 530232cbf..74a234aff 100644
--- a/.vsts-ci/linux/templates/packaging.yml
+++ b/.vsts-ci/linux/templates/packaging.yml
@@ -1,5 +1,5 @@
 parameters:
-  pool: 'ubuntu-16.04'
+  pool: 'ubuntu-20.04'
   parentJobs: []
   name: 'Linux'
 
diff --git a/.vsts-ci/misc-analysis.yml b/.vsts-ci/misc-analysis.yml
index d760a6e49..5de5e2826 100644
--- a/.vsts-ci/misc-analysis.yml
+++ b/.vsts-ci/misc-analysis.yml
@@ -51,7 +51,7 @@ jobs:
   displayName: Markdown and Common Tests
 
   pool:
-    vmImage: ubuntu-16.04
+    vmImage: ubuntu-20.04
 
   variables:
     - name: repoPath
diff --git a/.vsts-ci/templates/nix-test.yml b/.vsts-ci/templates/nix-test.yml
index 6a1b6e6f9..89c1a39dd 100644
--- a/.vsts-ci/templates/nix-test.yml
+++ b/.vsts-ci/templates/nix-test.yml
@@ -63,6 +63,18 @@ jobs:
     continueOnError: true
 
   - pwsh: |
+      Import-Module .\build.psm1 -Force
+      $environment = Get-EnvironmentInformation
+      $isUbuntu20 = $environment.IsUbuntu -and $environment.IsUbuntu20
+      if ($isUbuntu20) {
+        $env:LC_ALL='en_US.UTF-8'
+        $env:LANG='en_US.UTF-8'
+        sudo locale-gen $LANG
+        sudo update-locale
+      }
+
+      locale
+
       Import-Module .\tools\ci.psm1
       Restore-PSOptions -PSOptionsPath '$(System.ArtifactsDirectory)\build\psoptions.json'
       $options = (Get-PSOptions)
diff --git a/build.psm1 b/build.psm1
index f98872504..c87e11475 100644
--- a/build.psm1
+++ b/build.psm1
@@ -1223,7 +1223,13 @@ function Start-PSPester {
 
     if ($Unelevate)
     {
-        $outputBufferFilePath = [System.IO.Path]::GetTempFileName()
+        if ($environment.IsWindows) {
+            $outputBufferFilePath = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            # Azure DevOps agents do not have Temp folder setup on Ubuntu 20.04, hence using HOME directory
+            $outputBufferFilePath = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
     }
 
     $command += "Invoke-Pester "
@@ -1305,7 +1311,14 @@ function Start-PSPester {
 
     $PSFlags = @("-noprofile")
     if (-not [string]::IsNullOrEmpty($ExperimentalFeatureName)) {
-        $configFile = [System.IO.Path]::GetTempFileName()
+
+        if ($environment.IsWindows) {
+            $configFile = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            $configFile = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
+
         $configFile = [System.IO.Path]::ChangeExtension($configFile, ".json")
 
         ## Create the config.json file to enable the given experimental feature.
@@ -1384,7 +1397,13 @@ function Start-PSPester {
         {
             if ($PassThru.IsPresent)
             {
-                $passThruFile = [System.IO.Path]::GetTempFileName()
+                if ($environment.IsWindows) {
+                    $passThruFile = [System.IO.Path]::GetTempFileName()
+                }
+                else {
+                    $passThruFile = Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName())
+                }
+
                 try
                 {
                     $command += "| Export-Clixml -Path '$passThruFile' -Force"
diff --git a/test/powershell/Language/Parser/ParameterBinding.Tests.ps1 b/test/powershell/Language/Parser/ParameterBinding.Tests.ps1
index 7fd26912e..493ea9083 100644
--- a/test/powershell/Language/Parser/ParameterBinding.Tests.ps1
+++ b/test/powershell/Language/Parser/ParameterBinding.Tests.ps1
@@ -168,7 +168,13 @@ Describe "Custom type conversion in parameter binding" -Tags 'Feature' {
             }
         }
 '@
-        $asmFile = [System.IO.Path]::GetTempFileName() + ".dll"
+        if ($IsWindows) {
+            $asmFile = [System.IO.Path]::GetTempFileName() + ".dll"
+        }
+        else {
+            $asmFile = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName() + ".dll"))
+        }
+
         Add-Type -TypeDefinition $code -OutputAssembly $asmFile
 
         ## Helper function to execute script
diff --git a/test/powershell/Language/Scripting/ScriptHelp.Tests.ps1 b/test/powershell/Language/Scripting/ScriptHelp.Tests.ps1
index 8824d9620..7553fc962 100644
--- a/test/powershell/Language/Scripting/ScriptHelp.Tests.ps1
+++ b/test/powershell/Language/Scripting/ScriptHelp.Tests.ps1
@@ -180,7 +180,12 @@ Describe 'get-help HelpFunc1' -Tags "Feature" {
 Describe 'get-help file' -Tags "CI" {
     BeforeAll {
         try {
-            $tmpfile = [IO.Path]::ChangeExtension([IO.Path]::GetTempFileName(), "ps1")
+            if ($IsWindows) {
+                $tmpfile = [IO.Path]::ChangeExtension([IO.Path]::GetTempFileName(), "ps1")
+            }
+            else {
+                $tmpfile = Join-Path $env:HOME $([IO.Path]::ChangeExtension([IO.Path]::GetRandomFileName(), "ps1"))
+            }
         } catch {
             return
         }
@@ -233,7 +238,12 @@ Describe 'get-help file' -Tags "CI" {
 Describe 'get-help other tests' -Tags "CI" {
     BeforeAll {
         try {
-            $tempFile = [IO.Path]::ChangeExtension([IO.Path]::GetTempFileName(), "ps1")
+            if ($IsWindows) {
+                $tempFile = [IO.Path]::ChangeExtension([IO.Path]::GetTempFileName(), "ps1")
+            }
+            else {
+                $tempFile = Join-Path $env:HOME $([IO.Path]::ChangeExtension([IO.Path]::GetRandomFileName(), "ps1"))
+            }
         } catch {
             return
         }
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Management/Test-Connection.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Management/Test-Connection.Tests.ps1
index fc5cf7a69..c41b60c3e 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Management/Test-Connection.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Management/Test-Connection.Tests.ps1
@@ -96,7 +96,8 @@ Describe "Test-Connection" -tags "CI" {
             { Test-Connection "fakeHost" -Count 1 -ErrorAction Stop } |
                 Should -Throw -ErrorId "TestConnectionException,Microsoft.PowerShell.Commands.TestConnectionCommand"
             # Error code = 11001 - Host not found.
-            if ((Get-PlatformInfo).Platform -match "raspbian") {
+            $platform = Get-PlatformInfo
+            if ($platform.Platform -match "raspbian" -or ( $platform.Platform -match 'ubuntu' -and $platform.Version -eq '20.04')) {
                 $code = 11
             } elseif (!$IsWindows) {
                 $code = -131073
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Utility/Add-Type.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Utility/Add-Type.Tests.ps1
index b818dc640..72d42af1d 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Utility/Add-Type.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Utility/Add-Type.Tests.ps1
@@ -155,7 +155,13 @@ public class SMAAttributeTest$guid : PSCmdlet
 
         ## The assembly files cannot be removed once they are loaded, unless the current PowerShell session exits.
         ## If we use $TestDrive here, then Pester will try to remove them afterward and result in errors.
-        $TempPath = [System.IO.Path]::GetTempFileName()
+        if ($IsWindows) {
+            $TempPath = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            $TempPath = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
+
         if (Test-Path $TempPath) { Remove-Item -Path $TempPath -Force -Recurse }
         New-Item -Path $TempPath -ItemType Directory -Force > $null
 
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Utility/Set-PSBreakpoint.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Utility/Set-PSBreakpoint.Tests.ps1
index 21c84fe47..a5b809d8f 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Utility/Set-PSBreakpoint.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Utility/Set-PSBreakpoint.Tests.ps1
@@ -154,7 +154,14 @@ set-psbreakpoint -command foo
     }
 
     It "Fail to set psbreakpoints when script is a file of wrong type" {
-        $tempFile = [System.IO.Path]::GetTempFileName()
+
+        if ($IsWindows) {
+            $tempFile = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            $tempFile = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
+
         $ErrorActionPreference = "Stop"
         {
             Set-PSBreakpoint -Script $tempFile -Line 1
diff --git a/test/powershell/engine/Basic/Assembly.LoadFrom.Tests.ps1 b/test/powershell/engine/Basic/Assembly.LoadFrom.Tests.ps1
index 67ee0677c..383f20bfb 100644
--- a/test/powershell/engine/Basic/Assembly.LoadFrom.Tests.ps1
+++ b/test/powershell/engine/Basic/Assembly.LoadFrom.Tests.ps1
@@ -35,7 +35,14 @@ Describe "Assembly.LoadFrom Validation Test" -Tags "CI" {
 
         ## The assembly files cannot be removed once they are loaded, unless the current PowerShell session exits.
         ## If we use $TestDrive here, then Pester will try to remove them afterward and result in errors.
-        $TempPath = [System.IO.Path]::GetTempFileName()
+
+        if ($IsWindows) {
+            $TempPath = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            $TempPath = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
+
         if (Test-Path $TempPath) { Remove-Item -Path $TempPath -Force -Recurse }
         New-Item -Path $TempPath -ItemType Directory -Force > $null
 
diff --git a/test/powershell/engine/Basic/Assembly.LoadNative.Tests.ps1 b/test/powershell/engine/Basic/Assembly.LoadNative.Tests.ps1
index bb3835736..9196ccc0e 100644
--- a/test/powershell/engine/Basic/Assembly.LoadNative.Tests.ps1
+++ b/test/powershell/engine/Basic/Assembly.LoadNative.Tests.ps1
@@ -6,7 +6,13 @@ Describe "Can load a native assembly" -Tags "CI" {
     BeforeAll {
         ## The assembly files cannot be removed once they are loaded, unless the current PowerShell session exits.
         ## If we use $TestDrive here, then Pester will try to remove them afterward and result in errors.
-        $TempPath = [System.IO.Path]::GetTempFileName()
+        if ($IsWindows) {
+            $TempPath = [System.IO.Path]::GetTempFileName()
+        }
+        else {
+            $TempPath = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        }
+
         if (Test-Path $TempPath) { Remove-Item -Path $TempPath -Force -Recurse }
         New-Item -Path $TempPath -ItemType Directory -Force > $null
 
diff --git a/test/powershell/engine/Remoting/PSSession.Tests.ps1 b/test/powershell/engine/Remoting/PSSession.Tests.ps1
index 3b8259f37..25c7ab9c5 100644
--- a/test/powershell/engine/Remoting/PSSession.Tests.ps1
+++ b/test/powershell/engine/Remoting/PSSession.Tests.ps1
@@ -83,7 +83,8 @@ Describe "SkipCACheck and SkipCNCheck PSSession options are required for New-PSS
         if (
             ($platformInfo.Platform -match "alpine|raspbian") -or
             ($platformInfo.Platform -eq "debian" -and ($platformInfo.Version -eq '10' -or $platformInfo.Version -eq '')) -or # debian 11 has empty Version ID
-            ($platformInfo.Platform -eq 'centos' -and $platformInfo.Version -eq '8')
+            ($platformInfo.Platform -eq 'centos' -and $platformInfo.Version -eq '8') -or
+            ($platformInfo.Platform -eq 'ubuntu' -and $platformInfo.Version -eq '20.04')
         ) {
             Set-ItResult -Skipped -Because "MI library not available for Alpine, Raspberry Pi, Debian 10 and 11, and CentOS 8"
             return
diff --git a/test/powershell/engine/Remoting/RemoteSession.Basic.Tests.ps1 b/test/powershell/engine/Remoting/RemoteSession.Basic.Tests.ps1
index a8054b471..d56ed1999 100644
--- a/test/powershell/engine/Remoting/RemoteSession.Basic.Tests.ps1
+++ b/test/powershell/engine/Remoting/RemoteSession.Basic.Tests.ps1
@@ -15,6 +15,7 @@ Describe "New-PSSession basic test" -Tag @("CI") {
             ($platformInfo.Platform -match "alpine|raspbian") -or
             ($platformInfo.Platform -eq "debian" -and ($platformInfo.Version -eq '10' -or $platformInfo.Version -eq '')) -or # debian 11 has empty Version ID
             ($platformInfo.Platform -eq 'centos' -and $platformInfo.Version -eq '8') -or
+            ($platformInfo.Platform -eq 'ubuntu' -and $platformInfo.Version -eq '20.04') -or
             ($IsMacOS)
         ) {
             Set-ItResult -Skipped -Because "MI library not available for Alpine, Raspberry Pi, Debian 10 and 11, CentOS 8, and not compatible with macOS"
@@ -33,6 +34,7 @@ Describe "Basic Auth over HTTP not allowed on Unix" -Tag @("CI") {
             ($platformInfo.Platform -match "alpine|raspbian") -or
             ($platformInfo.Platform -eq "debian" -and ($platformInfo.Version -eq '10' -or $platformInfo.Version -eq '')) -or # debian 11 has empty Version ID
             ($platformInfo.Platform -eq 'centos' -and $platformInfo.Version -eq '8') -or
+            ($platformInfo.Platform -eq 'ubuntu' -and $platformInfo.Version -eq '20.04') -or
             ($IsMacOS)
         ) {
             Set-ItResult -Skipped -Because "MI library not available for Alpine, Raspberry Pi, Debian 10 and 11, CentOS 8, and not compatible with macOS"
@@ -56,6 +58,7 @@ Describe "Basic Auth over HTTP not allowed on Unix" -Tag @("CI") {
             ($platformInfo.Platform -match "alpine|raspbian") -or
             ($platformInfo.Platform -eq "debian" -and ($platformInfo.Version -eq '10' -or $platformInfo.Version -eq '')) -or # debian 11 has empty Version ID
             ($platformInfo.Platform -eq 'centos' -and $platformInfo.Version -eq '8') -or
+            ($platformInfo.Platform -eq 'ubuntu' -and $platformInfo.Version -eq '20.04') -or
             ($IsMacOS)
         ) {
             Set-ItResult -Skipped -Because "MI library not available for Alpine, Raspberry Pi, Debian 10 and 11, CentOS 8, and not compatible with macOS"
diff --git a/test/tools/Modules/WebListener/WebListener.psm1 b/test/tools/Modules/WebListener/WebListener.psm1
index 6436da97d..655b4cdd6 100644
--- a/test/tools/Modules/WebListener/WebListener.psm1
+++ b/test/tools/Modules/WebListener/WebListener.psm1
@@ -102,7 +102,7 @@ function Start-WebListener
         [int]$HttpPort = 8083,
 
         [ValidateRange(1,65535)]
-        [int]$HttpsPort = 8084,
+        [int]$HttpsPort = 9084,
 
         [ValidateRange(1,65535)]
         [int]$Tls11Port = 8085,
diff --git a/tools/packaging/packaging.psm1 b/tools/packaging/packaging.psm1
index 9b1602a09..000d48067 100644
--- a/tools/packaging/packaging.psm1
+++ b/tools/packaging/packaging.psm1
@@ -1351,21 +1351,21 @@ function New-AfterScripts
     Write-Verbose -Message "AfterScript Distribution: $Distribution" -Verbose
 
     if ($Environment.IsRedHatFamily) {
-        $AfterInstallScript = [io.path]::GetTempFileName()
-        $AfterRemoveScript = [io.path]::GetTempFileName()
+        $AfterInstallScript = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        $AfterRemoveScript = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
         $packagingStrings.RedHatAfterInstallScript -f "$Link", $Destination  | Out-File -FilePath $AfterInstallScript -Encoding ascii
         $packagingStrings.RedHatAfterRemoveScript -f "$Link", $Destination | Out-File -FilePath $AfterRemoveScript -Encoding ascii
     }
     elseif ($Environment.IsDebianFamily -or $Environment.IsSUSEFamily) {
-        $AfterInstallScript = [io.path]::GetTempFileName()
-        $AfterRemoveScript = [io.path]::GetTempFileName()
+        $AfterInstallScript = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
+        $AfterRemoveScript = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
         $packagingStrings.UbuntuAfterInstallScript -f "$Link", $Destination | Out-File -FilePath $AfterInstallScript -Encoding ascii
         $packagingStrings.UbuntuAfterRemoveScript -f "$Link", $Destination | Out-File -FilePath $AfterRemoveScript -Encoding ascii
     }
     elseif ($Environment.IsMacOS) {
         # NOTE: The macos pkgutil doesn't support uninstall actions so we did not implement it.
         # Handling uninstall can be done in Homebrew so we'll take advantage of that in the brew formula.
-        $AfterInstallScript = [io.path]::GetTempFileName()
+        $AfterInstallScript = (Join-Path $env:HOME $([System.IO.Path]::GetRandomFileName()))
         $packagingStrings.MacOSAfterInstallScript -f "$Link" | Out-File -FilePath $AfterInstallScript -Encoding ascii
     }