fatal error: runtime: cannot allocate heap metadata

[burgalon]

I'm docker under Dokku. When trying to run docker ps or even just docker I'm getting an error:

runtime: panic before malloc heap initialized
fatal error: runtime: cannot allocate heap metadata

Rummomg under DigitalOcean VPS Ubuntu 13 x64

[unclejack]

How much free RAM memory have you got? Are you running on a 512MB droplet?

[jpetazzo]

Are you out of memory?
Can you show the output of "free"?

[ghost]

I can confirm he's running on a 512M droplet

[dhassler]

I can confirm you see this message when out of memory, I experienced the same thing.

My solution on a 512MB droplet was to add a swapfile to the disk, and the problem went away.

[burgalon]

@dhassler Could you explain how to add a swapfile to disk?

[dhassler]

I would recommend doing a little bit of reading before making changes on your system, this article helped to refresh my memory.

In short, you do something like:

dd if=/dev/zero of=/extraswap bs=1M count=512
mkswap /extraswap

..and add it to /etc/fstab:

/extraswap         none            swap    sw                0       0

and then turn it on:

swapon -a

[crosbymichael]

I think this can be closed.

[cihangir]

A bit too late but i came across with this issue lately(not with docker)
echo 1 > /proc/sys/vm/overcommit_memory saved my work
you can read more about overcommit_memory here http://www.redhat.com/magazine/001nov04/features/vm/

[alana314]

Had this issue too on EC2. Followed this tutorial to increase swap. http://stackoverflow.com/questions/17173972/how-do-you-add-swap-to-an-ec2-instance

[matthewpalmer]

Simply rebooting the droplet worked for me.

[khedaywi]

Here's a good overview on adding a swapfile to Ubuntu, keeping the swapfile persistent and adjusting performance of the swapfile: https://www.digitalocean.com/community/tutorials/how-to-add-swap-on-ubuntu-14-04

To verify whether a swapfile has been setup, type this command:

sudo swapon -s

...if only these headers are return you should set up a swapfile to avoid running out of memory causing this issue:

Filename                Type        Size    Used    Priority