HP StorageWorks 6000 HP StorageWorks VLS and D2D Solutions Guide (AG306-96028, - Page 19

Figure 3 Basic Write-to-disk Setup . Table 1 VLS Compared to Application-based Write-to-disk Virtual tape devices Write-to-disk Setup and management complexity Sets up just like a physical tape library. Requires configuration of RAID groups, LUNs, volumes, and file systems. Data compression Software or hardware enabled (software compression generally decreases performance). No device-side data compression available. Performance Hardware devices are tuned for sequential Performance dependent on target array or read and write operations. server. More expensive acquisition cost. Cost Backup software licenses as if physical library or per TB. Storage efficiency gained through compression. Free or licensed per TB in most backup applications. Higher management overhead. Lower management overhead. Business Copy Using a business-copy solution (array snapshots/clones) generally involves a much higher cost than a virtual library system. You might, however, implement such a solution if: • Virtually instant recovery is critical. • You need to leverage a high-availability investment. • You are doing image recovery rather than file recovery. • You need a zero downtime solution. HP StorageWorks VLS and D2D Solutions Guide 19