HP Storage Mirroring Software - Manual (Page 619)

Recommended optimizations Page 618 of 677
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Disable root encryption—If the top-level folders in your replication sets are not
encrypted, you can gain a performance improvement by disabling root encryption.
This option is available under HKEY_LOCAL_
MACHINE\SOFTWARE\NSISoftware\Double-
Take\CurrentVersion\EnableRootEncryption. The value is hexadecimal. The valid
values are 0 to disable root encryption or 1 to enable root encryption. See Server
Settings in the Scripting Guide for more details on this option.
General manageability
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Temporary files—Some applications create temporary files that are used to store
information that may not be necessary to replicate. If user profiles and home
directories are stored on a server and replicated, some unexpected data may be
replicated if applications use the \Local Settings\Temp directory to store data. This
could result in significant amount of unnecessary data replication on large file
servers. Additionally, the \Local Settings\Temporary Internet Files directory can
easily reach a few thousand files and dozens of megabytes. When this is
multiplied by a hundred users it can quickly add up to several gigabytes of data
that do not need to be replicated. You may want to consider excluding temporary
data like this, however it is important to know how applications may use these
temporary files. For example, Microsoft Word creates a temporary file when a
document is opened. When the user closes the file, the temporary file is renamed
to the original file and the original file is deleted. In this case, you must replicate
that temporary file so that Storage Mirroring Recover can process the rename and
delete operations appropriately on the target.
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Enable replication set calculation by volume—If your replication set contains a
large number of files, for example, ten thousand or more, you may want to disable
the calculation of the replication set size so that data will start being mirrored
sooner. If calculation is enabled, the source calculates the file size before it starts
mirroring. This can take a significant amount of time depending on the number of
files and system performance. Disabling calculation will result in the mirror status
not showing the percentage complete or the number of bytes remaining to be
mirrored. The option CalculateByVolume can be enabled as a workaround. This
setting will get the amount of disk space in use for the entire volume from the
operating system, so the calculation occurs instantaneously. However, if the entire
volume is not being replicated, the mirror percentage complete and bytes
remaining will be incorrect accordingly. This option is available under HKEY_
LOCAL_MACHINE\SOFTWARE\NSISoftware\Double-
Take\CurrentVersion\CalculateByVolume. The value is hexadecimal. The valid
values are 0 to disable calculate by volume or 1 to enable calculate by volume.
See Server Settings in the Scripting Guide for more details on this option.