I have a small embedded board PC which uses flash card to boot and I'm running Ubuntu server 12.04. But since flash cards have limited lifetime I would like to mount it as read only and have only some folders in tmpfs for file operations.
I edited my fstab as follows:
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
UUID=0b2dc455-4dd0-4a4f-934c-587962b006c8 / ext4 ro,discard,noatime,nodiratime,errors=remount-ro 0 1
tmpfs /tmp tmpfs nodev,nosuid 0 0
tmpfs /var/log tmpfs nodev,nosuid 0 0
But since the system is read-only it doesn't mount tmpfs folders. Is there any way I can mount tmpfs on read-only filesystem?
EDIT
df -h
looks like this after startup:
Filesystem Size Used Avail Use% Mounted on
/dev/mmcblk0p2 7.4G 2.0G 5.5G 27% /
udev 450M 4.0K 450M 1% /dev
none 453M 0 453M 0% /run/shm