IBM ProtecTier Implementation and Best Practices Guide

182 IBM ProtecTIER Implementation and Best Practices Guide

12.1 Introduction

Many backup servers have features and settings that are used to optimize performance when

writing data to real tape cartridges. Because the ProtecTIER repository presents a VTL with

virtual drives and cartridges to the backup server, some settings that are optimized for real

tape are not required and might have a detrimental effect on the ProtecTIER factoring ratio

and performance. Check the current settings of your backup server and apply those settings

that can be implemented.

12.2 General recommendations

This section provides an overview of general recommendations regarding interoperability,

software, backup applications, tape, and SAN zoning recommendations that are common to

all backup servers. We also describe compression, encryption, multiplexing, tape block sizes,

and types of data targeted for backup.

12.2.1 Interoperability

Check the IBM Interoperability Matrix to ensure that the version of your backup server and

operating system are supported for the ProtecTIER product. Also ensure that your server

HBA is compatible with the ProtecTIER product. You can view the matrix at the

following website:

http://www-03.ibm.com/systems/support/storage/ssic/interoperability.wss

12.2.2 Software compatibility

Ensure that your backup server version platform and operating system version are listed in

the supported hardware and software list for the ProtecTIER product. You can view the list at

the following website:

http://public.dhe.ibm.com/common/ssi/ecm/en/ivl12348usen/IVL12348USEN.PDF

12.2.3 Software, backup application, and operating system

Ensure that the backup application software is updated to the latest version. This action can

impact the overall factoring performance. Also, ensure that the operating system of the

backup server is updated to the most recent patch or maintenance level. This action can

impact overall HyperFactor performance. For more information, see the following website:

http://www-03.ibm.com/systems/storage/tape/library.html#compatibility

12.2.4 Tape library zoning

The backup server must have a dedicated host bus adapter (HBA) port or ports for the

ProtecTIER VTL. This port or ports can be shared with a physical tape library. However, the

physical tape library must not be in the same storage area network (SAN) zone as the VTL.

When it is not possible to dedicate HBA ports for VTL and physical tape library, have different

zones to separate the traffic.

Chapter 12. Backup management introduction 183

Other SAN zoning recommendations

The following list provides recommendations common to all backup servers:

򐂰 Use zones based on the worldwide port name (WWPN).

򐂰 Use two-member zones, that is, one initiator port and one target port per zone. If not

possible, consider, at least, having one single initiator on each zone.

򐂰 Do not mix the front-end zoning (zoning between the ProtecTIER server and backup

application server) with the back-end zoning (zoning between the ProtecTIER server and

the ProtecTIER back-end storage).

򐂰 For each backup server, create a separate zone for each HBA that accesses ProtecTIER

virtual resources.

򐂰 Before creating worldwide name (WWN) zones on a SAN switch, you must get the WWPN

of each port for both your ProtecTIER server and your host computer.

򐂰 If you plan to use Control Path Failover (CPF), you can zone your host to all ProtecTIER

ports. You have more than one instance of the same robot recognized in the OS, but it is

ready when the CPF redirects the traffic to the other port without requiring

zoning changes.

򐂰 If you are not planning to use CPF, zone the host to some ports of the VTL, to balance the

backup traffic among the HBAs. Spread drives across the HBAs.

Table 12-1 is an example of a zone from a system where one backup application server has

two HBAs. The workload distribution between the two HBAs is needed and there is no

intention to use CPF. Each Tivoli Storage Manager HBA sees two ports of the VTL. The tape

devices in the OS appear only once, and the load is distributed.

Table 12-1 Example of a zone where load distribution is wanted

12.2.5 Compression

Compression scrambles the data sent to the ProtecTIER server, which makes pattern

matching difficult. This data scrambling affects data matching rates, even if the same data is

sent each time. The ProtecTIER product compresses the data it sends to the back-end

physical disk after the virtual tape drives receive and deduplicate the data. Disable any

compression features for the ProtecTIER that are defined for the backup server.

Port sharing: Although sharing a Fibre Channel (FC) port between physical and virtual

tape is possible when they are in different SAN zones, you should never share a port with

a disk SAN.

Initiator Target

TSM_HBA_Port0 VTL_FrontEnd_port0

TSM_HBA_Port0 VTL_FrontEnd_port2

TSM_HBA_Port1 VTL_FrontEnd_port1

TSM_HBA_Port1 VTL_FrontEnd_port3