Resizing Disk Partitions with PowerShell

Date Published: January 28, 2022

This guide explains how to resize partitions on Windows systems using PowerShell. These commands are useful when managing disk space for servers, virtual machines, or local machines.

Steps to Resize a Partition

Original Command:

$size = (Get-PartitionSupportedSize -DiskNumber 10 -PartitionNumber 2)
Resize-Partition -DiskNumber 10 -PartitionNumber 2 -Size $size.SizeMax

Explanation of the Commands

Get-PartitionSupportedSize:
- Retrieves the minimum and maximum sizes that a partition can be resized to.
- Parameters:
  - -DiskNumber: The identifier for the disk containing the partition.
  - -PartitionNumber: The identifier for the partition to be resized.
Resize-Partition:
- Resizes the partition to the specified size.
- Parameters:
  - -DiskNumber: The target disk.
  - -PartitionNumber: The target partition.
  - -Size: The new size of the partition, specified in bytes.

Enhancements for Usability

1. Dynamic Disk and Partition Selection

To make the command more dynamic, list available disks and partitions for selection:

Get-Disk | Select Number, Size, PartitionStyle
Get-Partition -DiskNumber 10 | Select PartitionNumber, Size

2. Resizing to a Custom Size

Instead of always resizing to the maximum size, you can specify a custom size (in bytes):

Resize-Partition -DiskNumber 10 -PartitionNumber 2 -Size 500GB

To convert GB to bytes:

$customSize = 500GB
Resize-Partition -DiskNumber 10 -PartitionNumber 2 -Size $customSize

Error Handling

Add error handling to ensure smooth execution:

try {
    $size = Get-PartitionSupportedSize -DiskNumber 10 -PartitionNumber 2
    if ($size.SizeMax -gt 0) {
        Resize-Partition -DiskNumber 10 -PartitionNumber 2 -Size $size.SizeMax
        Write-Host "Partition resized successfully."
    } else {
        Write-Host "No available space to resize the partition."
    }
} catch {
    Write-Host "An error occurred: $_"
}

Best Practices

Backup Data:
- Always back up important data before resizing a partition to avoid data loss in case of failure.
Check Disk Health:
- Use the following command to ensure the disk is healthy before resizing:
```
Get-PhysicalDisk | Where-Object HealthStatus -ne "Healthy"
```

Monitor Disk Usage:

After resizing, verify disk usage with:

Get-Volume | Select DriveLetter, Size, SizeRemaining