Using Powershell values from the start of the pipeline in a table at the end.

There are two ways to deal with large arrays of nested objects in powershell.

One is a bunch of nested foreach loops which is nicely readable in scripts.

However the beauty of the pipeline is that you can run output from one command into the input for another, which is often the way to drill down into dependent objects.

One such example is Vmware portgroups in Powercli.

The hierachy can be several levels deep

e.g.

cluster
 -> host
   -> vswitch
      -> portgroup

I wanted to build a table showing portgroups on all hosts in a cluster, ignoring the default management kernel port

The command is quite simple.

Get-Cluster -name Cluster01 | Get-VMHost | Get-VirtualSwitch -name vSwitch0 | Get-VirtualPortGroup | where {$_.name -ne "Management Network" | select Name, VirtualSwitch | ft -autosize

This produces a nice table showing the portgourp name and the vswitch it's connected to.

However the hostname isn't a property of the portgroup, it's a property of the vswitch (or the host) so the question is how to show it in the table.

The answer is with the pipelinevariable command (introduced in PS4 and above) and a custom property expression.

Get-Cluster -name Cluster01 Get-VMHost | Get-VirtualSwitch -name vSwitch0 -PipelineVariable 'fi' | Get-VirtualPortGroup | where {$_.name -ne "Management Network"} | select Name, VirtualSwitch, @{Name = "VMHost";Expression = {($fi.vmhost)}} | ft -AutoSize

This returns a nice table of three columns, with the third column

Error scanning Dell hosts with VUM "Host cannot download files"

This is one possible solution for the error "Host cannot download files from VMware vSphere Update Manager patch store. Check the network connectivity and firewall setup, and check esxupdate logs for details"


If you're running Dell hosts and Openmanage, there is an issue with the Openmanage VIB 8.2.0 - 8.5.0 (possibly other versions but these are the ones I've tested).

Unzip the file and have a look at the index.xml file



In my case the line containing the tag had a typo - you'd have thought Dell could spell their name, especially when it's only 4 characters long. 

Edit this to be Dell and re-zip the files (making sure the files are in the root of the zipfile)

 
 

The bad news is that you can't manually remove VIBs from the VUM database once they've been imported, so you basically have to nuke your VUM config so first make a note of all your baselines / baseline groups.

At least you no longer have to uninstall and reinstall the database - there is a tool called VMwareUpdateManagerUtility.exe in the Update Manager application folder which will reset the database.  Run it, point it at your VUM server, login and choose the Database settings -> re-initialize database option:





You should now be able to re-import the new VIB zipfile and perform a scan.

Unfortunately if you have alot of baselines or baseline groups, you'll need to recreate them.

Cannot create KDS Root Key - “Request is not supported”

When trying to run the powershell command Add-KDSRootKey –EffectiveImmediately you get the error "Request is not supported" if the powershell console isn't running elevated as administrator.

Just right click on the powershell icon and run as administrator and rerun the command.

V2V error with vConverter standalone - Unable to obtain hardware information for the selected machine.

When converting a VMWare workstation format VM (V2V) you might get this error if you're trying to read the image from a network path with a deep folder structure.

The simple resolution is to map a drive letter at the top level so the vmx and vmdk files are visible directly under the drive letter.

The converter wizard will then allow you to progress to specifying the destination system.

Windows 2012 - how to disable "run as administrator" requirement

So you've just installed Windows 2012..

The first thing you do is turn off UAC just like in Windows 2008 to stop it prompting you every time java wants to update.  Great! no more popups that you're just going to click ok to every time.

Then you remember you need to edit the hosts file, but what's this? You can't save it?  What's going on?

The answer is you need to edit it with notepad that's been "run as administrator".  But that's going to be a hassle isn't it, so how do you disable this and go back to Windows 2008 behaviour?

The answer is to edit a registry key which controls the EnableLUA setting:
HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA
Default value Windows 2008 = 0
Default value Windows 2012 = 1

You can do it via regedit or run the powershell below, in a powershell prompt that of course has been run as administrator:

Set-ItemProperty -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System" -Name "EnableLUA" -Value "0"

The server needs to be rebooted which you can do from powershell too:

shutdown -r -t 0

Hey presto, no more prompts.

Credit to this post for the solution.

Network Policy Server Role won't install on Windows 2008

I recently had a weird issue while trying to install TMG 2010 (Microsoft Threat Management Gateway) on Windows 2008R2 where the pre-requisites wouldn't install and kept giving an 0x80072afc error

I narrowed this down to the Network Policy Server role which wouldn't install.

Googling the error "windows could not start the network policy server services" along with the error code "0x80072afc" revealed quite a few articles, mostly relating to missing permissions on the IAS folder within the system directory and/or active directory issues.

I decided to take a clone of another known-working TMG as a workaround, but on this box the Network Policy Server service wouldn't start which led me to believe it wasn't permissions related.


The fix I eventually found was much simpler.  I'd been trying to install TMG with the server in a workgroup and disconected from the network.

I plugged in the network card so the server picked up an IP from DHCP and Hey Presto! the TMG pre-req wizard then completed ok!

Understanding DFS replication processes and what to do if it stops working

First of all, a quick introduction to Microsoft's DFSR - DFSR was introduced in Windows 2003 R2 and is the mechanism used to replicate files between servers.  This is especially useful when you are using DFS namespaces to publish file shares as you want all possible targets in DFS to have the same files on them.  If you're now lost, you should probably go and read up on DFS concepts on Microsoft's sites.

Now on to the nuts and bolts of how the DFS Replication service works.

The DFS Replication service maintains a database of filenames, paths and hashes in the system volume information\DFSR folder.  It also holds a copy of the database in memory when it's running.  There is only a single database *per drive letter*.  Do not mess with this!

DFSRPrivate is a symlink in each folder configured for replication which points to the DFSR database.
When the first member is added to a replication group, it’s designated primary and builds it’s database of file hashes.
During the build process it is marked as primary (check with dfsradmin membership list /RgName:xxxxx /Attr:MemName,RfName,IsPrimary where xxxxx is your replication group name - use the full path including the fqdn if present)
Once the database build is complete, the primary flag goes away and an Event 4112 is logged in the event log.  Also the replication state changes to 4.

e.g. (where dfsns is the namespace)

Before:
D:\>dfsradmin membership list /RgName:domain.local\dfsns\RepGroup1 /Attr:MemName,RfName,IsPrimary
MemName  RfName   IsPrimary
SERVER1 FOLDER1 Yes
D:\>Wmic /namespace:\\root\microsoftdfs path dfsrreplicatedfolderinfo get replicationgroupname,replicatedfoldername,state | find /I "FOLDER1"
FOLDER1      domain.local\dfsns\RepGroup1   0

After:
D:\>dfsradmin membership list /RgName:domain.local\dfsns\RepGroup1 /Attr:MemName,RfName,IsPrimary
MemName  RfName   IsPrimary
SERVER1  FOLDER1  No
D:\>Wmic /namespace:\\root\microsoftdfs path dfsrreplicatedfolderinfo get replicationgroupname,replicatedfoldername,state | find /I "FOLDER1"
FOLDER1  domain.local\dfsns\RepGroup1   4

If another server is introduced to the replication group while this process is happening, bad things ™ happen, so let it complete!  This can take several hours on very large servers.
The database is built with something called fence value assigned in the database against each file.  This is used in the event of conflicts (e.g. the same file being found in the same place on another server)

All files on the primary member are assigned the “Initial Primary” fence value.  This guarantees that this server is considered the authoritative server during  initial replication.  If another server is introduced before the initial database build is complete, that second server considers itself primary too, so it will assign the same fence value, hence conflicts and the bad things ™.

Once the database has been built, a second member can be introduced.  This will start building its database and assign the Initial Sync fence value to all files it finds (assuming there are existing files).  The second server will then compare the database with the first server and start copying over any missing or different files.

•    If a file doesn’t exist on the secondary member, it will just be copied over and it will move to the next file
•    If a file exists already, then the fence values are compared for conflict resolution.
   o    The higher fence value wins and overwrites the lower.  RDC (remote differential compression) is used to check the files for differences (comparing the file hashes) and changed blocks are copied to the second if required (usually nothing will be copied because the files are usually the same e.g. preseeded
   o    If they have the same fence value, the bad things ™ now occur as there is a conflict.  Conflict resolution is invoked and uses first create time, last modified time to decide which file should win. Conflicting files are moved to the DrfsPrivate\ConflictedandDeleted folder.
This means that the live data on the primary server is moved out of live shares. It will stay in the ConflictedandDeleted folder until it runs out of quota at which time it will be flushed.
This isn’t necessarily the end of the world because the file is still on the second server and *should* eventually be replicated back, but if a User is looking for their file before this happens, they will not see it.

More information on the sequencing can be found on the MS page here:

As indicated below, the Initial Primary fence (2) is higher than the initial sync value (1) which are the two values assigned during the initial setup of replication.

0 Unfence This file or folder will lose all conflicts.
1 Initial Sync Initial fence value for non-primary member.
2 Initial Primary Initial fence value for primary member.
3 Default Default fencing value.
4 Fence Fence with current time stamp.