Oracle安装报错：SGA size can not be greater than maximum shared memeory segment size

安装数据的时候报错：

查看操作系统参数设置：

[root@single1 ~]# vi /etc/sysctl.conf 
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536

# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
#kernel.shmmax = 68719476736
<span style="color:#FF0000;">kernel.shmmax = 1871947673</span>

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296


fs.aio-max-nr = 1048576
fs.file-max = 6815744
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576

看来是

<span style="color:#FF0000;">kernel.shmmax</span>

这个参数的限制。我相同主机上还有一个数据库：

SQL> show parameter sga
 
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
lock_sga                             boolean     FALSE
pre_page_sga                         boolean     FALSE
sga_max_size                         big integer 396M
sga_target                           big integer 0

相同系统下，dbca建库：

也就是说，单个数据库的sga只要不大于该限制即可。

那么还一种方案，修改操作系统限制：

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

当然，不要忘记

sysctl -p

重新dbca即可。（如果不重新dbca，还是会报错）