HP 9000 Virtual Library System - Manual (Page 56)

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
complete. 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 value to a number greater than zero to prevent aborted or multiple
mirror operations on a cartridge where the backup application mounts the cartridge,
writes to it, unmounts the cartridge, and then repeats this cycle multiple times during a
backup window.
•
At End of the Policy Window – what happens to active jobs when the policy window is
over. The options are Allow Active Jobs to Complete, Cancel Active Jobs, and Cancel
Active Jobs if Less Than 0% complete. If you select the last option, enter the percentage
completion in the field.
56 Automigration/Replication