分类： LINUX
2010-11-07 14:06:29
By default installation, RHEL and most Linux distributions mount tmpfs (a RAM-based temporarily filesystem) to /dev/shm directory and this temporarily filesystem size is always set to be half of the installed memory.
If that default size is not something expected, you can increase or reduce the /dev/shm filesystem size at wish.
To be even extreme, you may drop or disable this temporarily RAM-based filesystem entirely, to prevent it from auto-mount during system boots up, if none of the application in that Linux server relying on shared memory function or explicitly using tmpfs (as a quick-and-dirty trick to improve execution performance).
To increase or decrease /dev/shm filesystem size
1) Open /etc/fstab with vi or any text editor of your choice,
2) Locate the line of /dev/shm and use the tmpfs size option to specify your expected size,
e.g. 512MB:
tmpfs /dev/shm tmpfs defaults,size=512m<%2