HP ProLiant ML310 G3 Storage Server Administration Guide (WSS R2 version, March 2006)

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 d isks 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 filesmustbebroughtbackonlinewithin20minutes;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 exa mple, if user files are stored on H:\, another volume such as S:\ can be used to
store the s
hadow copies. Using a separate volume on separate disks provides better performance and is
recommen
ded for heavily used storage servers.
If a separ
ate volume will be used for the storage area (where shadow copies are store d), the maximum
size shou
ld be changed to No Limit to reflectthespaceavailableonthestorageareavolumeinsteadof
the sour
ce 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 ma intenance versus p er formance a nd
reliabi
lity that the system administrator must consider.
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) c
an 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 ma ximum of 64 shadow copies per volume, there is a trade-off between the
frequency of making shadow copies and the amount of time that the earlier files will be available.
By default, the storage ser ver 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 accommo date end user needs.
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File server management