Partitions: My Recommendations for Windows Deployments

Update 07/20/2015 – After looking into the Microsoft Surface Recovery Images, I have revised my recommendations.

If you had a look at my last post Partitions: The Defaults for Windows, MDT, CM and Technet you are well aware that there are some issues with consistency in Windows 7 and Windows 8.1 when it comes to Partition Sizes.  So here is what I recommend.

7-20-2015 12-13-47 AM


BIOS MBR Partition 1 – System 984MB

There are two variances in Partition 1 (the System Partition).  The first is the Label.  We have “System Reserved” (Media installs), “BDEDrive” (OSD), and “System” (MDT and Technet).  System is the obvious choice, as it is used 3 of the 6 times.  It is preferred over “BDEDrive” as there are instances where a system will not use Bitlocker, so naming it with a BDE in the name doesn’t make sense.  It is a System partition, that supports Bitlocker . . . it is not a Bitlocker Partition.  “System Reserved” is used but as a preference, I do not like drive labels with spaces in the name, whether this makes running queries a little more challenging, or the fact that it is not a name used for UEFI systems, make it an unlikely candidate.  So let’s just agree that the System Partition should just be named “System”.

The size is the second issue.  This is varied from 100MB – 499MB.  So let’s understand what goes in this partition.  In Windows 8.1, this partition will contain WinRE.  The default sizes of WinRE for Windows 8.1 is 202MB – 246MB, and 141MB – 165MB for Windows 7.  Obviously we can rule out on using the 100MB that Windows 7 Media adopted because it is not standardized.  This leaves us with 350MB, 499MB, and my recommendation of 984MB.  Keep in mind that if we wanted to add Microsoft DaRT to our WinRE implementation, our WinRE sizes increase.  Windows 8.1 x64 WinPE with DaRT consumes 443MB, without even adding Optional Components (PowerShell) or any drivers.  So we can now rule out the 350MB Partition as the standard since it is too small as well.  If I adopt the 499MB Partition Size, this leaves me with 56MB free.  Not really enough to add drivers and WinPE OC’s, but it may be possible to manage, but I need to be aware of Microsoft Volume Shadow Copy.  Apparently there are some rules.  Microsoft is kind enough to share them at Configure BIOS/MBR-Based Hard Drive Partitions.

System partition (with Windows RE tools)
Each bootable drive must contain a system partition. The system partition must be configured as the active partition.
The Windows Recovery Environment (Windows RE) tools image should be in a separate partition than the Windows partition to support automatic failover and to support booting Windows BitLocker Drive Encryption-encrypted partitions.
To avoid the four-partition limit on BIOS-based systems, we recommend adding the Windows RE tools image onto the system partition.
The minimum size of this combined partition is 350 MB.
This partition must allocate space for the Windows RE tools image (winre.wim, typically between 250-300MB, depending on base language and customizations added), plus enough free space so that the partition can be captured by backup utilities:
If the partition is less than 500 MB, it must have at least 50 MB of free space.
If the partition is 500 MB or larger, it must have at least 320 MB of free space.
If the partition is larger than 1 GB, we recommend that it should have at least 1 GB free.

So since the 499MB Partition is less than the 500MB limit, we must leave 50MB free.  This is not enough for the Boot files (17MB) and any additional customizations to WinRE.  TechRepublic has a great writeup on what issues you face when you don’t follow these rules in Fix the 0x80780119 error when creating a System Image in Windows 7 and 8

So why 984MB and not 600MB?  Because again, we have to follow rules.  Since 600MB is over 500MB, we need to keep 320MB of free space in this partition, which means this will only leave us with 280MB for WinRE and Boot, which is not possible.  984MB allows us to have 664MB of usable space.

So why 984MB and not 1000MB?  Again the rules.  If our partition is larger than 1GB, then we need 1GB of free space, so we need to make certain that we are as close to 1000, but not over.  If we specify 1000, it is impossible to Diskpart to use 1000 due to cluster size and alignment.  So we may be 999, or 1001, but to be safe, take 16MB aware to account for any crazy anomilies.

BIOS MBR Partition 2 – OSDisk Windows

We have the option of No Drive Label, OSDisk (OSD and MDT), or Windows.  Since we use MDT and OSD for Deployment, let’s just take this as the default.  Easy enough!  In production, the Windows label is used for Microsoft Surface Images, so it makes sense to adopt what Microsoft uses in their builds.


UEFI GPT Partition 1 – WinRE Windows RE tools 984MB

I am not sure why Microsoft can’t even agree on a name, even capitalizing the T in Tools, but the purpose of this partition is WinRE, and WinRE only.  Recovery was given to us by a Media install of Windows 8.1, but keep in mind we can also create a Recovery Image Partition at the end of the drive (I’ll detail this later) so having two drives with Recovery can be a bit confusing.  Again, we have the space in the name issue if we use “Windows RE tools”, that an noone uses the term “Windows RE”.  Every instance has been “WinRE” (win – arr – ee).  It just seems unnecessary, so I adopt “WinRE” only.  Don’t worry, Microsoft does mention using “WinRE” as a proper name in this link so I’m not suggesting doing something that Microsoft doesn’t suggest.

Now for the sizing of this partition.  Just like the System Partition for BIOS MBR, we have size rules.  Let’s just stick with 984MB.

UEFI GPT Partition 2 – System 100MB 200MB

This is the System Partition, and just like we did in the System Partition for BIOS MBR based configuration, keeping the name of “System” ensures consistency.

The size only needs to be 100MB 200MB as this is used for the Boot Configuration.  Since there is no need for WinRE in this Partition (UEFI has its own WinRE Partition), we do not need to consume 499MB (MDT) or 512MB (OSD) of space.  That and the 512MB configuration needs 320MB of free space due to the VSS issue.

UEFI GPT Partition 3 – MSR 128MB

Don’t change this!

UEFI GPT Partition 4 – OSDisk Windows

Exactly like we did for the Windows drive of BIOS MBR, let’s keep things consistent.

Let me know what you think of these recommedations and your configurations that you are using.  In a future post I will address how to make these changes in MDT and CM.