Hi,
Just read a tutorial on here about optimising hdd performance in w7. It talks about doing a disk wipe and then creating a boot partition using diskpart so you don't end up with the 'dreaded' 100mb (or was it gb) boot partition
My question really is what was so dreadful about this boot partition. Due to being a little naive - I'm not even sure what problems this tutorial is solving! Thanks
Matt
There is nothing dreadful about the 100MB partition. Seperating the MBR from the system is in fact a good idea - just think of a double boot. The downside though is that it takes up a primary partition and this together with the C and D partitions and a possible tools partition (in preinstalled OEM systems) saturates the system (4 primaries maximum in NTFS). Many people then do not know how to get out of this bind if they want to create an extra partition (e.g. a Data Partition) - many people who are not aware of the problem run into the dreaded dynamic partitions. But there are, of course, ways how to deal with it - not easy, but possible.
In an installation with a retail Win7 one does not have this problem because there is no D (recovery) partition and no tools partition. There the extra 100MBs really do not hurt.
Last edited by whs; 07 Oct 2010 at 14:21. Reason: typo
Ahh. My thanks for the explanation - the history makes sense of the present. Didn't know about the 4 max limit either.
Cheers
The original idea to do away with the dreaded 100MB boot partition was to reclaim as much space as possible from Solid State Drives (SSD) that had a small over-all size to start with; the "clean all" part of the tutorial has since shown it's worth in helping resolve installation issues where old Windows code being present is interfering with the installation process.
No problem, you won't know if you don't ask!
If you need a fourth "Primary" have a look at Option One of this tutorial.
Partition Wizard : Use the Bootable CD
I can only see 2 downsides to the separate 100MB partition:
1) Uses one of the 4 disk partitions. You can still use logical partitions if you want lots of partitions for some reason.
2) For some reason (which I don't understand) the 100MB partition can fill to greater than 50MB. When this happens you have problems with Windows imaging.
If 1) or 2) aren't of concern then I would just leave it alone but recognize that it contains the boot manager and the boot configuration data (BCD). It's critical to the booting of your computer.
The MBR (Master Boot Record) does not live in this 100MB partition. For BIOS booted PCs it is the first sector of the first track of the boot disk (first 512 bytes of the boot device inc USBs). It has a fixed physical location as well as data format.
There's an option to create a larger "System Reserved" and place it where you want and mark it "Active" before you start the Windows 7 install so that space won't be an issue, using the Partition Wizard boot disk.
Partition Wizard : Use the Bootable CD
click to enlarge
You shouldn't assign a letter to the System reserved partition. It's not for users to write to except when using tools like bcdedit to edit the boot configuration data. The OS can write to it.
Quote from Microsoft technical information:
"System Partition Requirements
Basic system partition requirements are:
- Must have at least 100 megabytes (MB) of hard drive space.
- Must have enough free space to create shadow copies of the partition.
- 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 gigabyte (GB), we recommend that it should have at least 1 GB free."
I thought this only applied to UEFI but clearly applies to BIOS boot as well. As stated the OS requires space for shadow copies of the partition.
There appears to be circumstances where the OS writes to the partition not leaving 50 MB of free space. When other users have found themselves in this situation they have problems with Windows imaging.
Then it may be helpful to get them to enlarge the size of the SysResv partition using something like the Partition Wizard boot disk, similar to Step One, then resize the SysResv into the free space created by the OS shrink; have a look at this tutorial for an out-line.
Dual Boot : Create Partitions Using PWBD
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