Identifying The Storage Area - HP ProLiant DL380 G5 Administration Manual

the frequency of changes to each file is greater than the amount of space allocated to storing shadow
copies, no shadow copy is created.
Administrators should also consider user expectations of how many versions they will want to have
available. End users might expect only a single shadow copy to be available, or they might expect three
days or three weeks worth of shadow copies. The more shadow copies users expect, the more storage
space administrators must allocate for storing them.
Setting the limit too low also affects backup programs that use shadow copy technology because these
programs are also limited to using the amount of disk space specified by administrators.
NOTE:
Regardless of the volume space that is allocated for shadow copies, there is a maximum of 64 shadow
copies for any volume. When the 65th shadow copy is taken, the oldest shadow copy is purged.
The minimum amount of storage space that can be specified is 350 megabytes (MB). The default storage
size is 10 percent of the source volume (the volume being copied). If the shadow copies are stored on a
separate volume, change the default to reflect the space available on the storage volume instead of the
source volume. Remember that when the storage limit is reached, older versions of the shadow copies
are deleted and cannot be restored.
CAUTION:
To change the storage volume, shadow copies must be deleted. The existing file change history that
is kept on the original storage volume is lost. To avoid this problem, verify that the storage volume
that is initially selected is large enough.
Converting basic storage disks to dynamic disks
When using a basic disk as a storage area for shadow copies and converting the disk into a dynamic
disk, it is important to take the following precaution to avoid data loss:
• If the disk is a non-boot volume and is a different volume from where the original files reside,
first dismount and take offline the volume containing the original files before converting the disk
containing shadow copies to a dynamic disk.
• The volume containing the original files must be brought back online within 20 minutes; otherwise,
the data stored in the existing shadow copies is lost.
• If the shadow copies are located on a boot volume, the disk can be converted to dynamic
without losing shadow copies.
NOTE:
Use the mountvol command with the /p option to dismount the volume and take it offline. Mount the
volume and bring it online using the mountvol command or the Disk Management snap-in.

Identifying the storage area

To store the shadow copies of another volume on the same file server, a volume can be dedicated on
separate disks. For example, if user files are stored on H:\, another volume such as S:\ can be used to
store the shadow copies. Using a separate volume on separate disks provides better performance and is
recommended for heavily used storage servers.
If a separate volume will be used for the storage area (where shadow copies are stored), the maximum
size should be changed to No Limit to reflect the space available on the storage area volume instead of
the source volume (where the user files are stored).
64
File server management