SAP Planning: Best Practices in Implementation System Landscape Best Practices
SAP System Landscape Best Practices and Rules of Thumb
Infrastructure/Network/Domain Best Practices
A separate domain for all W2K-based SAP resources is recommended by both SAP and its
technology partners (primarily for security purposes, as this minimizes the number of people that
have administrator access and can thus disable or change the SAP Services or
purposely/inadvertently delete SAP/database disk partitions). This also serves to keep extraneous
network/domain-related traffic off of the Enterprise SAP domain.
It is also recommended that separate subnets be deployed for the production SAP system and all
other SAP systems.
Further, in 3-tier configurations, the traffic between the Database Server and Application
Server(s) should reside on a separate high-speed (i.e. 100 Mbit/sec or GigE) subnet, hence the
need for at least TWO NICs in each Application Server – one NIC supports this back-end
network, and the other NIC supports the public network used by the SAPGUI/WebGUI clients.
For standardization purposes, these NICs should be IDENTICAL.
General Server Considerations
Only servers and Disk Subsystems (including disk controller/disk storage combinations)
specifically certified to support SAP may be proposed (though once a controller has been certified
in a particular vendor’s platform, it’s certified for all platforms).
More recently, SAP has left the Disk Subsystem certification up to the hardware vendor.
All volumes (OS/Pagefile, DB & SAP executables, and Log Files), except possibly the database
volume(s), should ALWAYS be configured for Hardware Level RAID 1. Database volumes may
be configured for any number of RAID levels, depending upon performance, availability,
redundancy, and other requirements.
All database volumes should be configured with a “Hot Spare” so as to minimize the potential for
losing yet another drive, and therefore losing data.
Pagefiles and Swap partitions are typically configured per SAP’s recommendation of 4 times
physical RAM (this actually varies, depending upon the specific Basis release and component
being deployed). However, greater than a 10 GB Pagefile/Swap is virtually pointless, as the SAP
formula does not apply well beyond a certain memory footprint.
Hardware vendors should never propose systems that exceed 65% expected CPU utilization. In
fact, many hardware partners size for 33% CPU load, keeping another 33% to address peaks or
batch loads, and the remaining 34% for emergencies/high seasonal peaks.
Tape Backup/Restore/Basic DR Strategy Best Practices
The Tape Solution specified for the Landscape should be standardized around a single density (or
backward-compatible to other densities in the Landscape), i.e. only 35/70 GB DLT drives will be
configured. Of course, this does not preclude use of different hardware tape subsystems - perhaps
a DLT Tape Array might be deployed for Production, and a shared Tape Library might be utilized
by all other systems, for example.
For the best level of protection, two tape drives should be used for Production - a separate tape
drive should be used to backup database LOGS, and another one used for database volume
backups. This maximizes the potential for successful backups/restores, as it protects against tape
drive problems that lead to corrupt media.
SAP Planning: Best Practices in Implementation System Landscape Best Practices
Regardless of physical devices, different tape cartridges must be used to backup the logs and the
database, again to ensure that the database can be restored – this protects against tape media
failure.
Network-based BACKUP/RESTORE servers are typically only recommended if a dedicated
Gigabit network link is implemented. Thus, we would now need 3 discrete NICs in a 3-tier
solution. The reason for the 3rd NIC is simple - potential bottlenecks associated with network-
based 100Mbit or slower networks, especially shared networks. It’s preferred to go with SAN-
based technology if your budget allows this, as described next.
The SAN Switched Fabric/Fibre-Channel based Tape Library keep backup/restore traffic off of
other networks. In the case of a SAN, a dedicated piece of gear is required to connect the SAN to
the tape library. As for FCAL systems, a dedicated 7 or 12-port Fibre Hub is necessary. Note that
many legacy 7-port Fibre Hubs are not “manageable,” though. On the other hand, not all 12-port
FCAL hubs supported Microsoft clusters. So do your homework in this regard – you may lean one
way or the other, for standardization, capability, or other purposes.