IBM ProtecTier Implementation and Best Practices Guide

Chapter 20. Application considerations and data types 309

򐂰 Use as many backup sessions in parallel as possible. The MAX_SESSIONS parameter

defines the number of parallel sessions to be established. The valid range of

MAX_SESSIONS is 1 - 32. You should also define the SESSIONS parameter in each Tivoli

Storage Manager stanza in the .utl file to define the maximum number of sessions in that

Tivoli Storage Manager server stanza.

򐂰 Disable compression by configuring RL_COMPRESSION=NO. The RL_COMPRESSION parameter

specifies whether a null block compression of the data should be performed before

transmission to Tivoli Storage Manager. Although RL_COMPRESSION introduces additional

processor load to the SAP server, throughput can be improved when the network is the

bottleneck, but it can affect the ProtecTIER deduplication ratio.

On the Tivoli Storage Manager server, complete the following steps:

1. Update the MAXNUMMP parameter for the Tivoli Storage Manager node to MAXNUMMP=x,

where x should be the number of parallels required. This number should match the

MAXSESSION parameter set in the .utl file. The MAXNUMMP parameter specifies the

maximum number of mount points a node may use on the server only for operations, such

as backup and archive.

2. Update the COMPression parameter for the Tivoli Storage Manager node to

COMPression=NO. This setting specifies that the client node does not compress its files

before sending them to the server for backup and archive.

20.7 VMware

In addition to the now available vStorage APIs, the vStorage APIs for Data Protection (VADP)

are also available. VADP replaces the VMware Consolidated Backup (VCB) framework, and

offers multiple methods to improve your VMware backup. With the new VADP comes the

option to use incremental virtual machine image backups, using the changed block tracking

(CBT) feature. In contrast to the full virtual machine image backup, CBT reduces the amount

of backed up data, because only the changed blocks compared to the last full backup are

backed up. With CBT enabled, the backup operation backs up only the changed blocks,

which results in a high data change rate for the ProtecTIER server, because only new data is

backed up. For ProtecTIER deduplication to perform optimally, run at least one full backup

per week.

Follow the general best practices and the Tivoli Storage Manager best practices described in

Chapter 13, “IBM Tivoli Storage Manager” on page 189.

20.7.1 Technical overview

VMware ESX is installed directly on the hardware and does not require any specific operating

system. It is a virtualization platform used to create the virtual machines (VMs) as a set of

configuration and disk files that perform all the functions of a physical machine.

Important: The MAX_SESSIONS parameter setting must not exceed the number of tape

drives simultaneously available to the node in the Tivoli Storage Manager servers to be

accessed. This maximum is established by the MAXNUMMP parameter settings in the

Tivoli Storage Manager node definition.

Incremental backups: If you use incremental virtual machine image backups, run at least

one full virtual machine image backup per week to optimize your deduplication ratio.