HP StoreOnce Backup - Manual (Page 12)

If you have selected D2DBS Generic for the Library Emulation Type, you will be able to select
Ultrium VT for the drive emulation. This is a generic Ultrium device which is clearly identifiable
as virtual. Backup application support for Ultrium VT is reasonable, but not quite as complete
as the D2DBS library type, so its not possible to use it with all backup software.
NOTE: Symantec prefer their customers to use this emulation type with BackupExec and
Netbackup.
•
HP 1x8 G2 Autoloader: This is a single Ultrium tape drive autoloader with a maximum of 24
cartridge slots. It should be used for simple rotation schemes where a single backup job is to
run at a time. This emulation type is widely supported by backup applications, but mainly of
use with the HP D2D2500 Series.
•
MSL G3 series (2x24) Library: This is a tape library device with a maximum of two embedded
Ultrium tape drives and 24 cartridge slots. It should be used when implementing rotation
schemes which involve simultaneous backup jobs to two devices. This emulation type is widely
supported by backup applications.
•
MSL G3 series (4x48) Library: This is a tape library device with a maximum of four embedded
Ultrium tape drives and 48 cartridge slots. It should be used when implementing rotation
schemes which involve simultaneous backup jobs to more than two devices or those that use
a large number of cartridges devices. This emulation type is widely supported by backup
applications.
•
MSL G3 series (8x96) Library: This is a tape library device with a maximum of four embedded
Ultrium tape drives and 96 cartridge slots.
•
ESL-E series Library: This is an enterprise tape solution which allows you to configure many
drives per library and many cartridges per library (see values for D2DBS emulation above).
Use the Show Details Box at the top of the screen to view maximum details and actual numbers
used.
•
EML-E series Library: This is an enterprise tape library solution which allows you to configure
many drives per library and many cartridges per library (see values for D2DBS emulation
above). Use the Show Details Box at the top of the screen to view maximum details for drives
and libraries and actual numbers used.
Flexible emulation (G2 products only)
If supported, the ESL, EML and D2DBS emulations are particularly flexible because they allow you
to configure a large number of drives per library. This has two main benefits:
•
It allows for more concurrent streams on backups which are throttled due to host application
throughput, such as multi-streamed backups from a database.
•
It allows for a single library (and therefore dedupe store) to contain similar data from backups
that must run in parallel to increase deduplication ratio.
If using these flexible emulation types, the following factors should also be considered:
•
Although there are no hard limits on the number of drives that can be configured per library,
there are limits on the total number of devices and shares that can be configured on an
appliance. If you configure 1 library with 200 drives on an HP D2D4312 Backup System,
you will still have 49 libraries available in theory, but you will have no more drives.
•
The total value also applies to NAS shares. If you configure the full 250 value as VTL devices,
you will not be able to configure any NAS shares for that appliance.
•
Please refer to the D2D Best Practices for VTL, NAS and Replication implementations for
maximum and recommended values.
NOTE: G1 products do not support flexible emulation; they have fixed values for the above
emulation types (some products do not support all emulation types).
12 Virtual Tape Devices