HP StorageWorks 6000-series Virtual Library System User Guide (AH809-96049, September 2010)

11. Type the desired policy settings in the corresponding fields. The policy settings differ for SAN
libraries and LAN/WAN libraries, and are as follows:
SAN libraries:
• Retention days – the number of days information is kept in the firesafe before it is deleted.
The default is two days.
• Sizing factor – the percentage of space, compared to the actual size of a disk, allocated on
the virtual tape for the copy job. For example, if the sizing factor is set to 90% and the
physical tape is 100 GB, the allocated space for the virtual tape will be 90 GB.
NOTE:
The sizing factor is crucial to creating the right size virtual tapes. When determining the sizing
factor of the virtual tapes, keep in mind the following:
• The sizing factor should be based on the size of the physical tape or the tape type if
possible. Common tape types and their sizes are: LTO-1 – 100 GB, LTO-2 — 200 GB,
LTO-3 — 400 GB, LTO-4 — 800 GB, DLT-IV — 80 GB, DLT-VS1 — 160 GB, SDLT-I —
320 GB, SDLT-II — 600 GB.
• HP recommends against setting the sizing factor too high (for example 110%). Although
the virtual copy can be made, if the drive compression is too low the data might not fit
back onto the physical tape.
• The sizing factor applies to all operations except Load for Restore, in which case the sizing
factor is ignored and the virtual copy is exactly the size of the physical cartridge.
• In general, the virtual cartridge is approximately 90% of the actual cartridge size. Base
the size of the copy on the eventual maximum size of the actual cartridge that is to be
copied.
• Source cartridge size limit — the size of all newly created source cartridges, regardless of
the physical cartridge size, on VLS systems with deduplication enabled. The default size is
200 GB; the maximum size is 300 GB.
Certain operations, such as loading physical cartridges into a copy pool with pre-existing
source cartridges, will require you to accept resizing the existing cartridges if they exceed
the size limit set here. In this case, a warning message indicates the number of cartridges to
be resized if you proceed. If you opt to continue and resize the source cartridges, no data
will be lost; you can still access data beyond the end of the newly set capacity limit.
The Sizing Factor also controls the size of the source cartridge. The system will size the source
cartridge using the Source cartridge size limit or the sizing factor, whichever value is the
smallest.
• Echo Copy on Source Cartridge Eject – When the backup application ejects an out of sync
virtual cartridge, the matching destination cartridge will not be ejected until the copy is com-
plete. When the copy on eject option is not checked, then the time to complete the copy and
eject the destination cartridge will depend on your start time and window size. When this
option is checked, then the copy will be started as soon as possible (depending on available
drives) regardless of start time and window size. Then the destination cartridge will be ejected.
• Send notification if cartridge not migrated in — the copy pool threshold. The system will send
a notification if this many hours have passed and the cartridges have not migrated.
• Start mirror of Out of Synch cartridges — When a cartridge goes into the ‘Out of Sync’ state,
you can schedule the mirror operation to begin only at the start of the policy window, or to
wait for the specified number of hours to pass after it enters the ‘Out of Sync’ state (provided
the time is within the policy window). The default is to schedule mirror jobs immediately upon
entering the ‘Out of Sync’ state provided the current time is within the policy window. Set this
HP StorageWorks 6000–series Virtual Library System User Guide 83