About the Accelerator feature in NetBackup 7.5 and later

Problem

Accelerator is a feature in NetBackup that combines the benefits of the O/S file system change journal, an Accelerator Track Log, deduplication and optimized synthetic backups. This minimizes the need to scan the entire file system for modified files (on Windows), minimizes the amount of data that needs to be backed up, and creates a synthesized full backup in approximately the time it takes to create an incremental backup. On volumes that do not change significantly, the backup may complete in 1/10th, 1/20th, 1/100th, or even less time. The performance gain is typically greatest for full backups, but may also benefit incremental backups.

Solution

Requirements and Options

1. NetBackup 7.5 or higher must be installed on the client, media server, and master server hosts.

2. The NetBackup Data Protection Optimization Option license (formerly known as the NetBackup Deduplication Option license) must be installed.

3. The policy type must be 'Standard' or 'MS-Windows'. (Additional policy types will be supported by future versions of NetBackup.)

4. The 'Use accelerator' option must be enabled in the policy attributes.

5. A storage unit used by the policy must support optimized synthetic backups; NetBackup PureDisk (MSDP, PureDisk, or appliance), Cloud storage plug-ins, and OpenStorage (OST) vendor qualified devices (see the NetBackup Hardware Compatibility List in the related articles or details).

6. If using a storage server that was configured using a version of NetBackup prior to 7.1, ensure that the OptimizedImage attribute is enabled. See the Related Articles for details.

7. For Window clients, it is recommended to enable the Windows NTFS Change Journal. This will allow backups to scan the change journal which is faster than scanning the entire file system.

   • Client Host Properties > Windows Client > Client Settings > Enable 'Use Change Journal'

Note: The Accelerator feature is not compatible with the following backup options.

• Storage units of type Basic Disk, Advanced Disk, or Tape.
• Client side encryption or compression.
• Backup Selections that specify a UNC path are supported in NB 7.5.0.1 and higher.
• Mapped drives are compatible, but are not enabled for NTFS change journal.

Troubleshooting

The following evidence is useful when troubleshooting issues with Accelerator.

From the primary/master server host:

• Job Details
• nbsu
• bpdbm debug log

From the media server host:

• bpbrm debug log
• bptm debug log

From the client host:

• bpbkar debug log
• bpinetd debug log (Windows only)
• bpcd debug log
• zip of the install_path\NetBackup\track directory (Windows), or tar of the /usr/openv/netbackup/track directory (UNIX/Linux)