[Container-tools] things i noticed about docker in abd

[Langdon White]

Hi,

I am not sure Burr had the default configuration for the ADB but, I 
believe he did. He ran out of disk space for docker images and I took a 
look at his machine. I noticed a couple things you may want to address:

1) the size of the /  partition seems ridiculously large at 20G (he had 
about 7G used, so maybe 10?)
2) the docker storage setup was using devicemapper. Would it make more 
sense and be faster to use one of the other storage options? I could 
have misread the docker-storage conf file as it has been a while since i 
have looked at one.
3) I also thought that the docker data size was kinda small at 6g given 
the vm has a 40g thinly provisioned disk.

this is more of an enhancement, as a user of ADB, Burr did not have a 
good idea for 1) how to extend the size of his docker storage, 2) how to 
do it safely, 3) how to clean up his crufty images.

I would propose:
1) modify docker-storage-setup to have an "easy" mode that takes a param 
for metadata size, disk size, and device/lvm-pool
2) doc with above to restart docker
3) add in vpavlin's (i think they were his) handy set of aliases for 
docker image/container cleanup

just some ideas from being there when Burr was trying to fix up his 
docker in ADB :)

langdon