[INS-35172] Target database memory (XXXMB) exceeds the systems available shared memory ({0} MB) solution

If you receives the above error while installation of Oracle database, Please follow as below.

You are trying to use the MEMORY_TARGET feature. This feature requires the /dev/shm filesystem to be mounted for at least maximum size than you specified at the time of installation. 

df -h /dev/shm will show you the current size of your shared memory file system.

[oracle@node1 Desktop]$ df -h /dev/shm

Filesystem            Size  Used Avail Use% Mounted on

tmpfs                 504M  272K  503M   1% /dev/shm

The size of this file is the real size of the key control AMM.  Modify the size of the tmpfs greater than the size of MEMORY_TARGET. Modify the /etc/fstab file  like below.

To adjust the shared memory file system size issue the following commands, specifying the required size of shared memory. However this is temporary

# umount tmpfs
# mount -t tmpfs shmfs -o size=2G /dev/shm

Make the setting permanent by amending the "tmpfs" setting of the "/etc/fstab" file to look like this.
After the above change if you check shared memory file system value will effect like below.

[oracle@node1 Desktop]$ df -h /dev/shm

Filesystem            Size  Used Avail Use% Mounted on

tmpfs                     2G  272K  2G   1% /dev/shm

Before:

*******

[root@node1 ~]# cat /etc/fstab

#

# /etc/fstab

# Created by anaconda on Sat Jan 10 19:24:12 2015

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

/dev/mapper/vg_node1-lv_root /                       ext4    defaults        1 1

UUID=510fd298-43dc-419d-a3ae-829e999d2430 /boot                   ext4    defaults        1 2

/dev/mapper/vg_node1-lv_swap swap                    swap    defaults        0 0

tmpfs                   /dev/shm                tmpfs   defaults        0 0

devpts                  /dev/pts                devpts  gid=5,mode=620  0 0

sysfs                   /sys                    sysfs   defaults        0 0

proc                    /proc                   proc    defaults        0 0

After:

*****

[root@node1 ~]# cat /etc/fstab

#

# /etc/fstab

#Created by anaconda on Sat Jan 10 19:24:12 2015

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

/dev/mapper/vg_node1-lv_root /                       ext4    defaults        1 1

UUID=510fd298-43dc-419d-a3ae-829e999d2430 /boot                   ext4    defaults        1 2

/dev/mapper/vg_node1-lv_swap swap                    swap    defaults        0 0

tmpfs                   /dev/shm                tmpfs   defaults,size=2G  0 0

devpts                  /dev/pts                devpts  gid=5,mode=620  0 0

sysfs                   /sys                    sysfs   defaults        0 0

proc                    /proc                   proc    defaults        0 0

To avoid reboot after editing /etc/fstab you can do:

umount tmpfs
mount -a

Happy Learning :)