> For the complete documentation index, see [llms.txt](https://osd.osdeploy.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://osd.osdeploy.com/docs/trash/disk/new-osdisk/old-version/partition-sizes.md).

# Partition Sizes

I don't recommend changing the Partition sizes from the defaults, as I consider them '**Perfect**'.  The only real difference between MBR and GPT is the MSR Partition for UEFI GPT layout

```
SYSTEM - 260MB | GPT MSR 16MB | WINDOWS - REMAINDER | RECOVERY - 990MB
```

**And when I say 'Perfect', this layout mirroring between MBR and GPR allows you to convert from MBR to GPR without moving around any partition data**

![](/files/-LqtAFA5Ey5wed4M5YUv)

## SizeSystemMbr

```
#System Partition size for BIOS MBR based Computers
#Default = 260MB
#Range = 100MB - 3000MB (3GB)
#Alias = SSM, Mbr, SystemM
[Alias('SSM','Mbr','SystemM')]
[ValidateRange(100MB,3000MB)]
[uint64]$SizeSystemMbr = 260MB
```

## SizeSystemGpt

```
#System Partition size for UEFI GPT based Computers
#Default = 260MB
#Range = 100MB - 3000MB (3GB)
#Alias = SSG, Efi, SystemG
[Alias('SSG','Efi','SystemG')]
[ValidateRange(100MB,3000MB)]
[uint64]$SizeSystemGpt = 260MB
```

## SizeMSR

```
#MSR Partition size
#Default = 16MB
#Range = 16MB - 128MB
#Alias = MSR
[Alias('MSR')]
[ValidateRange(16MB,128MB)]
[uint64]$SizeMSR = 16MB
```

## SizeRecovery

```
#Size of the Recovery Partition
#Default = 990MB
#Range = 350MB - 80000MB (80GB)
#Alias = SR, Recovery
[Alias('SR','Recovery')]
[ValidateRange(350MB,80000MB)]
[uint64]$SizeRecovery = 990MB
```