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.
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
By keeping the shadow copy on the same volume, there is a potential gain in ease of setup and maintenance; however, there may be a reduction in performance and reliability.
CAUTION:
If shadow copies are stored on the same volume as the user files, note that a burst of disk input/output (I/O) can cause all shadow copies to be deleted. If the sudden deletion of shadow copies is unacceptable to administrators or end users, it is best to use a separate volume on separate disks to store shadow copies.
Determining creation frequency
The more frequently shadow copies are created, the more likely that end users will get the version that they want. However, with a maximum of 64 shadow copies per volume, there is a
By default, the storage system creates shadow copies at 0700 and 1200, Monday through Friday. However, these settings are easily modified by the administrator so that the shadow copy schedule can better accommodate end user needs.
Shadow copies and drive defragmentation
When running Disk Defragmenter on a volume with shadow copies activated, all or some of the shadow copies may be lost, starting with the oldest shadow copies.
P4000 G2 Unified NAS Gateway User Guide 75
