182 IBM ProtecTIER Implementation and Best Practices Guide
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.
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
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:
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:
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
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
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
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.