Table of Contents
Advertisement
Load balance your virtual devices across the ports. For example, if you have a four-port
configuration and you configure a 24-drive library, you should spread the drives evenly across
the ports. Ensure that your backup application also balances the drive distribution.
With VLS9X00 and VLS12X00, you can upgrade capacity as needed after the initial setup.
To prepare for future expansion, the user should configure additional drive bays and slots on
the virtual robot to avoid having to delete and recreate the virtual library when expanding
capacity.
In firmware version 6.0 and higher you have the same number of virtual drives per node
regardless of whether deduplication is enabled. However, in version 3.x, if you initially deploy
without deduplication (with a maximum virtual drives per node of 128) but you intend to
enable deduplication in the future, you should limit the maximum number of virtual tape drives
per node to the deduplication limit which is 96 virtual devices (robots and libraries) per node.
This will make the migration to deduplication easier.
If possible, configure eight or fewer LUNs (virtual devices, including the robot) per port. Some
operating systems will not see more than this. If you need more than eight devices on a port,
you must use LUN mapping and masking.
HP recommends that you do not delete individual tape drives from inside the virtual library.
Deleting drives in the virtual library introduces gaps in the LUN numbering for shared
(unmapped) virtual tape drives, and many operating systems fail to scan the virtual tape drives
that follow a gap. In multi-node configurations, it can change drive element addresses. In both
cases, when the device reboots it will reorder the LUNs/elements of the tape drives and may
require reconfiguration of the media server tape paths.
If you use LUN mapping and masking to assign specific virtual drives to specific backup media
servers, make sure that the LUN numbering stays in sequence with no gaps. Instead of deleting
tape drives, you can disable them. (You can present them to a new host in the future if required.)
When creating virtual cartridges inside the virtual library, it is good practice to keep the virtual
cartridge size smaller than the physical tape. Generally it is always better to create smaller cartridges
than larger ones because it frees up the cartridge quicker for use by other processes such as restore,
tape copy, or deduplication processing. Cartridge sizes of 100 GB (the default size) are common
and this size can be used regardless of the tape emulation type because the cartridge is virtual
(you can create a 100 GB cartridge even if you selected LTO4 drive emulation). If copying to
physical tape via the backup application, the virtual cartridge size does not have any to match
the physical tape in any way (type, size, library type, drive type) because the backup applications
all perform "object copy" where they effectively backup the backup and therefore append and
span copy jobs onto the physical tapes just like they would with backup jobs. If copying to physical
tape via automigration, this will require the virtual cartridges to contain the same amount of data
as the physical tape and so automigration will automatically create the correct size virtual cartridges
to match the physical tapes.
EVA Preparation
Before you connect the VLS12X00 Gateway to the external EVA consider these concepts and
perform the related tasks:
The VLS12X00 attachs to a properly functioning EVA running firmware v. 5.0 or higher. Ensure
that your EVA meets these requirements before connecting to a VLS12X00.
Before installing the VLS12X00, ensure that the external Fibre Channel switch/fabric has either
two external Fibre Channel switches/fabrics or two zones. This is required so that there are
two data pathways from the VLS to the EVA. Dual pathing provides path balancing and
transparent path failover on the VLS12X00.
Implementation
57
Advertisement
Table of Contents
