Installation guide

Recommendaons for Oracle Component Placement
Oracle is sensive to read performance and sensive to write performance on the redo log les and on the archive log les. Thus, the
following recommendaons are given.
OS Volume - The OS should be installed on a RAID 1 disk volume. It is important that you do not need to restore/rebuild the OS in
the event of a disk failure. This can be very me consuming and expensive. The OS will certainly t on one disk drive, and RAID 5 is
generally not supported in a 2 drive conguraon. In addion, the Oracle binary les can be placed on this volume.
Redo Log Files - The Redo Log les should be placed on a RAID 1 or RAID 10 volume. The I/Os to the Redo Log les are 100% se-
quenal and 100% writes, thus RAID 5 is inappropriate.
Data Files - The Data les should be RAID 10 if the I/Os are 90% reads or less. If the I/O paern is 90% or greater reads, then RAID
5 is OK. Again, your budget may help determine this.
Archive Log Files - The Archive Log les can either be RAID 10 or RAID 5, depending on your budget. Archiving might take longer
if it is RAID 5.
By using RAID fault tolerant volumes, much pain and expense can be avoided in the event of a disk failure.
Conguring Server Memory
One of the challenges in conguring Oracle databases on Microso Windows is in choosing the appropriate amount of RAM. This is
parcularly true on 32-bit implementaons of Microso Windows, such as Windows Server 2000 and the 32-bit version of Windows
Server 2003. Due to inherent limitaons in the 32-bit architecture, it is not possible to access more than 4 GB of memory in a single
memory segment. This places some limitaons on Oracle SGA (System Global Area) size. By default, Oracle SGA sizes are limited to
2 GB or less. On Windows an Oracle instance runs as a single process. This process is a standard Win32 applicaon that is able to
make memory allocaons from the 2GB virtual address space. All memory allocaons made by all user connecons and background
threads have to t into 2GBs including global allocaons such as the buer cache. For systems that have either large user populaons
or buer cache requirements this presents a problem.
Large Memory Implementaon
Some help may be obtained by ulizing a feature known as 4 GB RAM Tuning (4GT). By seng the /3GB ag in the Windows boot.ini
le, Oracle SGA sizes up to 3 GB are supported. The OS and all other processes must use the remaining 1 GB of usable memory.