When you are using a tmpfs drive to speed up certain files/folders (eg var/cache from a Magento webshop), and your assigned amount of memory is too small, you can easily increase this by doing the following:
Modify your tmpfs mount in /etc/fstab to look something like this: (let’s say that I’ve changed the size of 64M to 128M
tmpfs /var/www/webshop/wwwroot/var/cache tmpfs size=128M,mode=0777,uid=33,gid=33 0 0
You can then remount the tmpfs drive by typing
mount -o remount tmpfs
To verify, simply type
df -h
Note: Be careful not too increase it too much! Your system will deadlock since the Out-Of-Memory handler can not free up that space if needed