Kernel panic on DigitialOcean upgrading to 1.4 with 1GB RAM

[prologic]

After upgrading to Rancher OS v1.4 on DigitalOcean Droplets the boot process kernel panics.

[prologic]

Upgrading the Droplet to 2GB of RAM resolved this.

[prologic]

Q: Why does Rancher OS v1.4 require 2GB of memory just to boot up? This is unacceptable as now a single Rancher OS instance on Digital Ocean costs you a minimum $10.00/month

[niusmallnan]

We added more features in 1.4, which caused it to need more memory when booting up. The next release will optimize this memory problem. Current memory requirements are mentioned here: https://rancher.com/docs/os/v1.x/en/#hardware-requirements

[prologic]

What was added that blew the bootup memory requirements from 1GB to 2GB?

[niusmallnan]

Initrd needs to load system-images, it includes user-docker, base-image, console-image, etc. The larger the images, the more memory is used.

We change the default user-docker to 18.03, this has caused system-images to become large, requiring 1280MB of memory at bootup.

[SvenDowideit]

does that mean that setting the user-docker to alpine in the cloud-init would reduce it again?

[thaJeztah]

We change the default user-docker to 18.03, this has caused system-images to become large, requiring 1280MB of memory at bootup.

What docker version was it using before that?

[ghost]

i run into the same prob. With RancherOS 1.2, a droplet with 1GB memory was enough.

[ghost]

# ros -v
version v1.2.0 from os image rancher/os:v1.2.0

# system-docker version
Client:
 Version:      library-import
 API version:  1.23
 Go version:   go1.8.5
 Git commit:   library-import
 Built:        library-import
 OS/Arch:      linux/amd64

Server:
 Version:      library-import
 API version:  1.23
 Go version:   go1.8.5
 Git commit:   library-import
 Built:        library-import
 OS/Arch:      linux/amd64

[niusmallnan]

@thaJeztah

What docker version was it using before that?

17.09.1

[niusmallnan]

In the next version, I will reduce system-docker and default console.

For user-docker, will also keep the latest stable-ce version.

[prologic]

Rather than complain about the latest Rancher OS being a resource (memory) hog at bootup and idle (with no user containers running) I decided to roll my own called MCL

I sincerely hope later versions of Rancher OS become more resource efficient