db2安装前需要修改配置内核参数,修改/etc/sysctl.conf shmall默认是8g，建议将此参数设置为db2服务器物理内存的90%，如果内存是16g，就是(16*0.9*1024*1024)/4=3774873,当前环境的物理内存是2g，也就是(2*0.9*1024*1024)/4=471859 shmmax建议和系统物理内存
db2安装前需要修改配置内核参数,修改/etc/sysctl.conf
shmall默认是8g，建议将此参数设置为db2服务器物理内存的90%，如果内存是16g，就是(16*0.9*1024*1024)/4=3774873,当前环境的物理内存是2g，也就是(2*0.9*1024*1024)/4=471859
shmmax建议和系统物理内存相等，在64位系统上必须至少设置为1g，即1073741824
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
net.ipv4.tcp_syncookies = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.msgmni = 1024
kernel.shmmax = 2147483648
kernel.shmall = 471859
kernel.sem = 250 256000 32 1024
kernel.randomize_va_space = 0
创建libpam.so软链接，具体参考ibm db2解决方案 
ic87092: db2prereqcheck gives warning the 32-bit library file libpam.so is not found on the system. when the required libpam.so.0 exist
[root@db2test server]# ln -s /lib/libpam.so.0.81.5 /lib/libpam.so
安装db2软件
[root@db2test server]# ./db2setup 
dbi1190i  db2setup is preparing the db2 setup wizard which will guide
you through the program setup process. please wait.