Quest Vranger Active Block Mapping And Hp Storeonce Backup System Deduplication; Vranger Resource Management - HP StoreOnce D2D2500 Implementation Manual

Figure 5: Enable Change Block Tracking in vRanger
Quest vRanger Active Block Mapping and HP StoreOnce Backup System
Deduplication
The vRanger backup and replication engine ignores whitespace (unallocated blocks or zero-filled blocks) by default.
Additionally, vRanger offers the option to enable Active Block Mapping (ABM) on a per-job basis.
ABM increase backup efficiency of Windows virtual machines by only including blocks that are actively used. ABM
verifies that deleted data is not included in the backup job. This means that with ABM enabled, vRanger will only
backup the part of a virtual disk that has active data on it. The benefit is smaller backups sent over the network to the
StoreOnce Backup System and a shorter backup window. However, compared to backups made without ABM, the
use of ABM will result in lower deduplication ratios as reported by the StoreOnce Backup System because vRanger
will reduce the amount of backup data sent to the appliance. It is important to measure the end-to-end data
compaction not just the deduplication ratio reported by the StoreOnce Backup System. This is covered in more depth
below.

vRanger resource management

The vRanger Resource Manager (Figure 6) enables control of the number of backup and replication of tasks to run
simultaneously. These controls allow fine tuning of vRanger to achieve greater throughput without impacting the
performance on VMware hosts, Datastores, and Repositories (StoreOnce Backup System).
These settings can be tuned depending on the environment; the default settings are a good starting point for testing. If
all backups are completed successfully with the default settings, the number of backups per Host, Datastore,
Repository, and locally (on Hot Add and Proxy server modes) can be increased. The potential increase can be
estimated from the reported load on the hardware.
If all backups do not complete successfully, the default settings should be decreased.
It is important not to run more concurrent backups streams than the StoreOnce Backup System is specified for. See the
Maximum concurrent vRanger backup streams per appliance values in Figure 7 for configuration maximums.
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