Not sure if this is the right forum for this, but we’ve been running docker in production for a while and realized that our default loop-back storage engine was still in use on our Centos machines. After trying a few options we got the best speed of spinning up new instances using the overlay storage engine so we switched to that.
We’re running probably ~30-45 containers at any given time on each machine processing though various queues. Around 3-4 machines get cycled per minute, and another ad hoc process probably create about 5-10 more, so we probably get around 10-15 machines being created a minute. We periodically get this error: “Error response from daemon: mkdir /var/lib/docker/overlay/3851fa644830e4f2aefa2d789cc43b75be43f8869b41cb003472ddbae948459a-init/merged/dev/pts: cannot allocate memory”
We have a swap set up, and in general are well under both our physical memory limit and ram limit, and the hard drive also has considerable space open.