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Oracle Linux 6 -- Cannot initialize tmpfs size set with /etc/fstab (Doc ID 1535495.1)

Last updated on OCTOBER 12, 2020

Applies to:

Linux OS - Version Oracle Linux 6.0 to Oracle Linux 6.3 [Release OL6 to OL6U3]
Oracle Cloud Infrastructure - Version N/A and later
Linux x86-64
Linux x86


tmpfs, which is a on-memory temporary filesystem, can be created and mounted on Linux. Be default, the tmpfs filesystem is set to be 50% of physical memory size. The size of the filesystem can also be set to the size set in mount option, such as size=<N> with suffix of k, m, or g, as well as %. It is also possible to set the size in /etc/fstab so that tmpfs can be mounted upon boot.

However, on Oracle Linux 6 (up to 6.3), the initial tmpfs size is always set to the default size regardless of the option set in /etc/fstab.

Example: Physical Memory = 800MB

We set the following line in /etc/fstab so that /dev/shm is mounted as tmpfs with 30% of memory size.


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