Oracle 10G Sga Sizes In Red Hat Enterprise Linux 3, 4 Or 5 - Red Hat ENTERPRISE LINUX 5.1 - LINUX ORACLE Tuning Manual

Chapter 16. Growing the Oracle SGA to 2.7/3.42 GB in x86 Red Hat Enterprise Linux 3, 4 and 5 Without VLM
08048000-0804c000 r-xp 00000000 03:45 1531117
0804c000-0804d000 rw-p 00003000 03:45 1531117
08fa0000-08fc1000 rw-p 08fa0000 00:00 0
b7df9000-b7ff9000 r--p 00000000 03:45 68493
b7ff9000-b7ffa000 rw-p b7ff9000 00:00 0
bffa6000-c0000000 rw-p bffa6000 00:00 0
ffffe000-fffff000 ---p 00000000 00:00 0
#
The outputs show that the mapped base is already very low in Red Hat Enterprise Linux 3, 4 or 5. In
the above example shared libraries start at 0xa38000 (decimal 10715136) in Red Hat Enterprise Linux
3 and 0xb68000 (decimal 11960320) in Red Hat Enterprise Linux 4 and 5. This is much lower than
0x40000000 (decimal 1073741824) in Red Hat Enterprise Linux 2.1:
# cat /etc/redhat-release
Red Hat Linux Advanced Server release 2.1AS (Pensacola)
# cat /proc/self/maps
08048000-0804c000 r-xp 00000000 08:08 44885
0804c000-0804d000 rw-p 00003000 08:08 44885
0804d000-0804f000 rwxp 00000000 00:00 0
40000000-40016000 r-xp 00000000 08:08 44751
40016000-40017000 rw-p 00015000 08:08 44751
40017000-40018000 rw-p 00000000 00:00 0
40022000-40155000 r-xp 00000000 08:08 47419
40155000-4015a000 rw-p 00132000 08:08 47419
4015a000-4015f000 rw-p 00000000 00:00 0
bffea000-bffee000 rwxp ffffd000 00:00 0
#
The above mappings show that the Mapped Base Address does not have to be lowered in Red Hat
Enterprise Linux 3 or 4 to gain more SGA space.
16.3. Oracle 10g SGA Sizes in Red Hat Enterprise Linux 3, 4
or 5
The following table shows how large the Oracle 10g SGA can be configured in Red Hat Enterprise
Linux 3, 4 or 5 without using a shared memory file system. Shared memory file systems for the SGA
Section 14.8, "Huge Pages and Shared Memory File System in Red Hat Enterprise
are covered at
Linux 3"Configuring Very Large Memory (VLM).
Red Hat 10g Database
Enterprise Version
Kernel Type
smp kernel (x86) 10g Release 1
hugemem kernel 10g Release 1
(x86)
56
/bin/cat
/bin/cat
/usr/lib/locale/locale-archive
/bin/cat
/bin/cat
/lib/ld-2.2.4.so
/lib/ld-2.2.4.so
/lib/i686/libc-2.2.4.so
/lib/i686/libc-2.2.4.so
Default Max Supported
Supported SGA SGA without
without VLM VLM
Up to 1.7 GB Up to 2.7 GB
Up to 2.7 GB Up to 3.42 GB
Comments
10g R1 must
be relinked to
increase the SGA
size to approx 2.7
GB
10g R1 must
be relinked to
increase the SGA
size to approx
3.42 GB