Extend VM Disk Using Powershell

In our earlier post we showed you how to extend the EBS volume of EC2 instances from AWS and OS end. Today we are going to provide you a similar PowerShell script to extend the VM disk from Vcenter as well as from the OS level with a single click.

As we use the VM, it gets filled with data and will require us to extend the drive. It becomes complex to get which disk to extend from Vcenter when there is more than one Disk with the same capacity.

This script solves that problem by matching the SCSI controller and extending the correct disk.

It asks for the VM Name, Drive letter, and the amount of disk to be increased as input and does the extension from Vcenter as well as from the OS end.

Please find the complete script below and experience the magic of PowerShell.

This Script will also check and warn you if the snapshot exists for the VM and makes sure that your datastore capacity will not reduce to less than 20% after extending the drive to the requested amount.

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Domain Controller Health Check

Active Directory or Domain Controllers are the most important part of your domain and organization. Hence they must remain healthy and work perfectly all the time. There are many parameters on which the health of the domain depends, either its services, replication, DNS, etc. Checking all those parameters takes a lot of time and if your domain contains a lot of domain controllers it becomes really difficult to check all the parameters or it takes a lot of time. 

Checking the Active Directory Health manually requires you to check the below things:

1. Make sure that all the Domain Controllers are replicating with each other.

To check the replication status of your Active Directory you need to run the repadmin /replsummary command which summarises the replication status of all the domain controllers in all the domains in your forest.

2. Make sure that all the dependency services are running fine.

You need to check the status of some critical services which are important for your active directory domain like ADDS Service, DFS Replication Service, DNS Server Service, Intersite Messaging Service, Netlogon Service, KDC Service, etc.

3. Use the Domain Controller Diagnostic Tool (DcDiag) to check some important aspects of the Domain.

DcDiag is an important tool for AD Administrators to check the various aspects of Active Directory like DNS. for a Domain to work to perform efficiently you need to make sure that your DNS resolution is happening perfectly. You can use this tool to the health of DNS by running the command dcdiag /test:DNS

By keeping the above time and effort taking steps in mind we at MagicPowershell comes up with an automated one-click script that will find all the DCs in your forest, run the health check on them and send an automated HTML script on completion to your email ID.

You need to modify a few parameters like SMTP server emails and run it to get the report in your inbox in a few minutes.

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Extend live EBS volume on AWS EC2 instance

Over time, EBS volume may get full and you need to increase its size.It's a common scenario where you need to increase the size of the disk attached to an EC2 instance. AWS makes it possible to increase the size of the volume while it's being actively used.

Sometimes it becomes complex to figure out which EBS volume to increase as there are multiple EBS volumes attached to an EC2 having the same size.

We at MagicPowershell today come with a PowerShell script that will solve this complex problem. The script will ask for the Drive letter, Size, and the EC2 instance name which needs to be resized.

Script Performs 3 tasks: 1. Finding the EBS volumeId based on the DriveLetter.

                                       2. Extending the EBS volume accordingly.

                                       3. Extending the windows file system after EBS volume resized.

 

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Set Delete On Termination Flag for EBS volume attached to an EC2 Instance

 When an EC2 instance terminates, the value of DeleteOnTermination attributes defines whether to preserve the EBS volumes attached to that EC2 instance or delete it.

By default, the value of this attribute is set to true for root volumes and false for other volumes.

So if you leave the values of the flag to default for all the volumes, the EBS volumes apart from the root volumes will not be deleted and adds up to your monthly AWS bill.

In order to avoid such unnecessary addons on your bill, you have to set the attribute value to true on each of the EBS volumes. But AWS doesn't give the option to set this flag if you add the volume to an already running EC2 instance.

We at MagicPowershell are here to solve this problem by providing a solution to set that attribute value to true for all the volumes attached to the EC2 instance using Powershell.

This Script will ask for the EC2 instance name on which you want to enable the Delete On Termination Flag and enables it on all the attached EBS volumes of the EC2 Instance.

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Create & Attach EBS volume to already running Windows EC2 Instance with PowerShell

After deploying an EC2 instance, there may be a need to add EBS volume to EC2 instance. You can add EBS volume to a running instance. This PowerShell script will automate the process of attaching additional EBS volume to Windows EC2 instance and after that, it will initialize, format the disk & assign a disk label. 

To attach additional EBS volume, we need to use block device mapping. Block device mapping defines the block devices (EBS volumes) that attach to an instance. The root volume is always attached to "/dev/sda1", it is mounted as C:\ in the Windows instance. Subsequent volumes are attached as "xvdf" devices. For Windows instance, you should use "xvdf-z", in order: xvdf, xvdg, xvdh, and so on.

 
To get the device name, the script uses the function Get-Device. This function automates the generation of device names in sequence xvdf, xvdg. The function takes Instance Id as a parameter. It checks the current attached devices first and generates new device name & returns it. If the current device is "/dev/sda1" then it returns "xvdf" otherwise it calculates subsequent devices and returns.

The next script block is the main script block, which takes parameters- instance name, volume size, volume type (gp2, io1, etc) & device. Using the instance name it finds the instance id and gets the device name by calling the Get-Device function. Note, it also finds the availability zone for instance so that volume is created in that zone.

Next, it creates a new volume with the New-EC2Volume command. We wait till the volume becomes available & once it is available attach it to the instance. Further, we do tagging for volume.

Once the volume is attached to an instance, call another function Initialize-EC2Disk to initialize, format the disk & assign a drive letter to the volume. In this function, we use the AWS Systems Manager tool to run PowerShell commands remotely on an EC2 instance. Using the automation feature of Systems Manager you do not require remote PowerShell to execute commands on the instance. For this first, create IAM role which will be used to give Systems Manager permission to run commands on the instance.

We use Send-SSMCommand to send PowerShell commands to instances. These commands will be executed on instance & format the attached volume.

In this way, you can automate adding EBS volume to the Windows instance and initializing & formatting volume.

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