WARNING: You are trying to use the MEMORY_TARGET feature.

Oracle 11G

WARNING: You are trying to use the MEMORY_TARGET feature.
This feature requires the /dev/shm file system to be mounted for at least 3338665984 bytes.
/dev/shm is either not mounted or is mounted with available space less than this size.
Please fix this so that MEMORY_TARGET can work as expected.
Current available is 1995063296 and used is 2177781760 bytes.
Ensure that the mount point is /dev/shm for this directory.
memory_target needs larger /dev/shm

Solución:
Cambiar el tamaño de /dev/shm segun lo requerido, aca dice 3338665984 bytes que son aproximadamente 4GB
mount -o size=4G -t tmpfs tmpfs /dev/shm
Para que quede permanente agregar al fstab
tmpfs /dev/shm tmpfs size=4g 0 0