Archived from groups: microsoft.public.win2000.setup (More info?)

What are the downsides to using Dynamic Disks? We want to use a software
RAID, but I am afraid of running into problems later on with this Dynamic
Disk format.
 
Tim

Archived from groups: microsoft.public.win2000.setup (More info?)

Dear Tim,
 
Thank you for posting!
 
From the origional message, I know that you want to use a software RAID,  
but you are afraid of running into problems later when using dynamic disk.
 
The below information is quoted from the article "317587 - HOW TO: Disable  
the Upgrade Basic Disks to Dynamic Disks Functionality" in the Microosft  
Knowledge Base:
 
A dynamic disk is a physical disk that contains dynamic volumes that you  
create by using Disk Management. Dynamic disks do not use traditional  
partition tables like primary and extended partitions (logical drives);  
therefore, dynamic disks cannot be accessed by MS-DOS, Microsoft Windows  
95, Microsoft Windows 98, Microsoft Windows Millennium Edition (Me) or  
Microsoft Windows NT operating systems.
 
When you convert a basic disk to a dynamic disk,  the partition layout on  
the disk changes and the dynamic disk database is created. These  changes  
provide you with increased flexibility to  manage the  volume in Windows  
2000 and Microsoft Windows XP Professional. However, these changes are not  
easily reversed, and the structure of dynamic disks is not compatible with  
some operating systems. Therefore, you must consider the following issues  
before you convert basic disks to dynamic disks:
 
- Do not convert a basic disk to a dynamic disk if it contains multiple  
copies of Windows XP Professional or Windows 2000. Even though these  
operating systems support dynamic disks, they require certain registry  
entries to start from dynamic disks. If the operating systems are installed  
on the same disk and you use one of the operating systems to convert the  
disk to a dynamic disk, the registry of the other operating system becomes  
out-of-date because the drivers that are required to start the operating  
system from a dynamic disk are not loaded. Therefore, you can no longer  
start the other operating system. You can use dynamic disks with Windows XP  
Professional and Windows 2000 in a multiple-boot configuration if you  
install each operating system to a different disk. For example, install  
Windows 2000 on disk A and Windows XP Professional on disk B. Use Windows  
2000 to convert disk A to a dynamic disk, and then use Windows XP  
Professional to convert disk B to a dynamic disk. By using this method, you  
ensure that the registries are updated for each operating system.
 
-  You can access dynamic disks only from computers that are running  
Windows 2000, Windows XP Professional, or Windows XP 64-Bit Edition. You  
cannot access dynamic disks from computers that are running MS-DOS, Windows  
95, Windows 98, Windows Me, Windows NT 4.0 or earlier, or Windows XP Home  
Edition. This restriction also means that you cannot start any of these  
operating systems if you convert the disk that contains the system volume  
to a dynamic disk.
 
To avoid this restriction, use two hard disks. Install the other operating  
system on the first disk, which contains the system volume, and then  
install Windows on the second disk. If you use this method, you can convert  
the disk that is running Windows to a dynamic disk and still start the  
other operating system on the basic disk. However, this method prevents the  
other operating system from accessing the dynamic disk or any of its  
volumes and data. Therefore, in computers that start multiple operating  
systems, you must use caution when you convert basic disks to dynamic disks.
 
The partition style that is used on the dynamic disk can also restrict  
access to dynamic disks.  The following list describes the different  
partition styles and their limitations:  
 
 - Dynamic master boot record (MBR) disks: Only computers that are running  
Windows 2000, Windows XP Professional, or Windows XP 64-Bit Edition can  
access dynamic MBR disks.
 
 - Dynamic GUID partition table (GPT) disks (where GUID is the abbreviation  
for globally unique identifier): Only Itanium-based computers that are  
running Windows XP 64-Bit Edition can access dynamic GPT disks.NOTE:    
Volumes on dynamic MBR and GPT disks are available across a network to  
computers that are running MS-DOS, Windows 95, Windows 98, Windows Me,  
Windows NT 4.0 or earlier, or Windows XP.
 
- Do not convert a basic disk to a dynamic disk if the disk contains  
unknown partitions that are created by other operating systems. Windows  
converts unknown partitions to dynamic partitions, which makes them  
unreadable to other operating systems.
 
- Do not convert a disk to a dynamic disk if it contains an original  
equipment manufacturer (OEM) partition that is not located at the beginning  
of the disk. (In Disk Management, an OEM partition typically is displayed  
as an EISA configuration partition.) When you convert a basic disk to a  
dynamic disk, Windows preserves the OEM partition only if this partition is  
the first partition on the disk. If this partition is not the first  
partition, the partition is deleted when the disk is  
  converted to a dynamic disk.
 
- You can extend dynamic volumes that do not retain their partition entries  
in the partition table. The following list describes the volumes that  
retain their entries in the partition table and cannot be extended:  
 
 - The system volume and boot volume of the operating system that you used  
to convert the disk to dynamic.
 
 - Any basic volume that was present on the disk when you converted the  
disk from a basic disk to a dynamic disk by using the version of Disk  
Management that is included with Windows 2000.
 
 - Simple volumes on which you run the DiskPart retain command. The retain  
command adds a partition entry to the partition table. However, after you  
use this command, you can no longer extend the volume.  
To add more space to the system volume or boot volume on a dynamic disk,  
you must   back up all of the data on the disk, repartition and reformat  
the disk, reinstall Windows, convert the basic disks to dynamic disks, and  
then restore the data from backup.  
 
The following volumes do not have partition entries and can be extended:  
 
 - Simple volumes and spanned volumes that are created from unallocated  
space on a dynamic disk.
 
 - A basic volume that is not the system volume or the boot volume, but it  
is on a disk that you converted from a basic disk to dynamic disk by using  
Windows 2000.  
In addition, you cannot extend striped volumes. Although striped volumes do  
not have entries in the partition table, you cannot extend this volume in  
Windows 2000. To add more space to a striped volume, back up the data,  
delete the volume, recreate the volume by using Windows 2000, and then  
restore the data.
 
- Disk Management does not offer FAT as a formatting option for dynamic  
volumes because the NTFS file system is the preferred file system for  
dynamic volumes. If you want to format a dynamic volume by using FAT, use  
My Computer, Microsoft Windows Explorer, or the format command.
 
- The DiskPart command that is used in the Recovery Console can damage your  
partition table if the disk has been upgraded to a dynamic disk. Always use  
Disk Management to modify the structure of dynamic disks.
 
- Windows 2000 does not support reverting your boot disk from a dynamic  
disk to a basic disk.
 
- Dynamic disks are not supported on the following hardware:
 
 - The Institute of Electrical and Electronics Engineers (IEEE) 1394 serial  
bus
 
 - The Universal Serial Bus (USB)
 
 - Removable disks
 
 - Disks in laptop computers or laptop docking stations
 
For additional information, visit the hyperlink below to view the article  
in the Microsoft Knowledge Base:
 
http://support.microsoft.com/?id=317587
317587 HOW TO: Disable the Upgrade Basic Disks to Dynamic Disks  
Functionality
 
http://support.microsoft.com/?id=175761
175761 Dynamic vs. Basic Storage in Windows 2000
 
I hope that the above information is helpful.  
 
Thank you for choosing Microsoft and have a nice day!
 
Thanks & Regards,
 
Feng Mao [MSFT], MCSE  
Microsoft Online Partner Support
 
Get Secure! - www.microsoft.com/security
 
=====================================================
When responding to posts, please "Reply to Group" via your newsreader so  
that others may learn and benefit from your issue.  
=====================================================
This posting is provided "AS IS" with no warranties, and confers no rights.