For the last seven hours or so I am getting messages that my docker disk utilization is high - it gets up to around 76% and then will generally fall back below 70%.  I haven't changed anything on my system. 

 

How do I troubleshoot this?  Does this mean that the usage for one particular docker is high, or for all of the dockers in aggregate?

 

I have installed Cadvisor but I don't know what to look for.  In the meantime I am getting spammed by notifcations and emails about this - which I guess I can turn off, but how do I fix this?

 

Here is an example of the notification:

Docker high image disk utilization: 11-07-2017 21:29
Warning [HOYLAKE] - Docker image disk utilization of 75%
Docker utilization of image file /mnt/user/system/docker/docker.img

 

22 minutes ago, wayner said:

all of the dockers in aggregate

How large is docker.img?

 

23 minutes ago, wayner said:

How do I troubleshoot this?

Several ideas in Docker FAQ

 

The two main culprits are missed mappings and excessive logging, both covered.

 

Deleting and recreating individual Dockers from their templates is an easy way to reset them to an initial size to remove bloat.

How do I find the size of docker.img?  I don't see it on the Dashboard - where do I look in the UI or do I need an SSH session to find this out?

 

I deleted a few dockers that I wasn't using much and this has caused things down a bit, but overnight it did happen again.

 

Dashboard will show the percentage of how full it is (Var / Log / Docker)

 

Actual size is shown under Settings / Docker  (Advanced View)

I still can't find anything on the Dashboard but in Settings/Docker under btrfs filesystem show it says:

 

Label:  none uuid: yada yada

Total devices 1 FS bytes used 10.76GiB

devid 1 size 20.00GiB used 16.02GiB path /dev/loop0

 

But this doesn't really jive with the Virtual Size reporting that I see from the Docker page of Cadvisor.  That only shows about 5GiB used if I add up all of the listings under Virtual Size.

 

It also doesn't correspond to a df -k  which shows that /dev/loop0 mounted on /var/lib/docker is 59% full