Allocating Disk Space; Identifying The Storage Area - HP StoreEasy 1000 Storage Administrator's Manual

Although shadow copies are taken for an entire volume, users must use shared folders to access
shadow copies. Administrators on the local server must also specify the \\servername\
sharename path to access shadow copies. If administrators or end users want to access a previous
version of a file that does not reside in a shared folder, the administrator must first share the folder.
NOTE: Shadow copies are available only on NTFS, not FAT or FAT32 volumes.
Files or folders that are recorded by using Shadow Copy appear static, even though the original
data is changing.

Allocating disk space

When determining the amount of space to allocate for storing shadow copies, consider both the
number and size of files that are being copied, as well as the frequency of changes between
copies. For example, 100 files that only change monthly require less storage space than 10 files
that change daily. If 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:
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.

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 systems.
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).
Disk space for shadow copies can be allocated on either the same volume as the source files or
a different volume. There is a trade-off between ease of use and maintenance versus performance
and reliability that the system administrator must consider.
64 File server management
To change the storage volume, shadow copies must be deleted. The existing file