I'm using the latest CoreOS AMI (ami-0fc25a0b6bd986d03 details) on a small
This instance only has 500MB of memory. Unfortunately, CoreOS immediately consumes ~240MB for a tmpfs, which it then mounts at
/tmp as shown below. This seems to completely eat my
shared memory and I cannot launch containers. Is there any way to reduce the size of this? Or perhaps some way to mount /tmp onto the root filesystem?
I'm considering abandoning CoreOS solely because I cannot get it to work with small instance sizes, which is a shame since I chose it specifically because it was supposed to be a tiny OS that gets out of the way and let's me run containers...
$ free -h total used free shared buff/cache available Mem: 479Mi 232Mi 7.0Mi 199Mi 238Mi 34Mi Swap: 0B 0B 0B $ df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 219M 0 219M 0% /dev tmpfs 240M 0 240M 0% /dev/shm tmpfs 240M 488K 240M 1% /run tmpfs 240M 0 240M 0% /sys/fs/cgroup /dev/xvda9 14G 2.8G 9.9G 22% / /dev/mapper/usr 985M 791M 143M 85% /usr none 240M 200M 41M 84% /run/torcx/unpack tmpfs 240M 0 240M 0% /media tmpfs 240M 0 240M 0% /tmp /dev/xvda6 108M 112K 99M 1% /usr/share/oem /dev/xvda1 127M 53M 74M 42% /boot tmpfs 48M 0 48M 0% /run/user/500
Edit: Perhaps relevant, RancherOS apparently requires a minimum of 1GB to launch, although their GitHub discusses values from 512MB up to 2GB. Unclear to me why these "tiny OS" have such relatively high RAM needs. For context, Debian minimum is 256MB on a headless install