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
More about :dynamic disk
July 5, 2004 6:53:23 AM
Archived from groups: microsoft.public.win2000.setup (More info?)
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
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out-of-date because the drivers that are required to start the operating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
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
- 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:
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