Overland Storage REO 9000 setup guide Reviewing Pre-Installation Requirements, Tape Emulation

Overland Storage REO 9000 with ProtectionPAC Software

If you use a RAID 5 configuration, you can also set aside a disk drive for each physical host (controller); that is, you can create a hot spare. These disk drives remain in standby mode, and you can use them immediately if another disk fails.

Tape Emulation

The ProtectionPAC software includes two tape emulation features, which you can use to create virtual linear tape-open (LTO-2) tape devices that provide 2-to-1 compression ratios with typical data sets (actual performance might vary with application). When you use tape emulation, the disk drives on the REO Appliance appear to your backup software as LTO-2 tape drives, which simplifies the setup process while simultaneously providing data compression and the attributes of backing up data to disk.

Depending on the configuration that you use, you get a different number of virtual LTO-2 devices. In the just-a-bunch-of-disks (JBOD) configuration, you can have up to 24. If you use RAID 0 or 5 without logical volumes, you can have four. If you use logical volumes with RAID 0 or 5, you can create up to 64 virtual LTO-2 devices.

If you decide to use tape emulation, you also have the option of using fixed-length (Tape) or dynamic-length (Dynamic Tape) devices. To take advantage of the Dynamic Tape option, you must use logical volumes, which is described in the next section. Using Dynamic Tape lets you create devices that adjust to the size of individual backup jobs.

Logical Volume Management (LVM)

With LVM, you can combine the two physical RAID volumes into multiple logical volumes (partitions) of different sizes and assign logical unit numbers (LUNs) to represent the different volumes, or REO devices. This feature lets you set up and assign devices to different systems according to your needs and the configuration and type of storage network that you use.

Using this feature in the ProtectionPAC software, you can create up to 64 LUNs, and you can reassign space allocation for disk or standard (not dynamic) virtual tape devices, in 1 gigabyte (GB) increments, on the fly.

Reviewing Pre-Installation Requirements

Before attempting to operate the REO Appliance with your backup servers, verify that your network meets the minimum requirements specified in the following sections.

Important: If you purchased multiple units, set up (attach and configure) one unit at a time. The target names must be unique within a network; that is, if you are using multiple appliances, you must change the default target names.

Also, be aware that the keys are not interchangeable and Overland strongly recommends that you make a backup copy of the files on the keys before and after you configure them.

16 X Reviewing REO 9000 Concepts and Requirements