I have setup docker and I have used completely different block device to store docker's system data: [root@blink1 /]# cat /etc/sysconfig/docker # /etc/sysconfig/docker other_args="-H tcp://0.0.0....

Reading through the documentation of both dm-crypt and LUKS, I understand that LUKS is a format specification to allow FDE, and that dm-crypt is a dm target which allows encryption / decryption of ...

I have a docker environment with 2 containers (Jenkins and Nexus, both with their own named volume). I have a daily cron-job which deletes unused containers and images. This is working fine. But th...

I am using Docker version 17.06.0-ce on Redhat with devicemapper storage. I am launching a container running a long-running service. The master process inside the container sometimes dies for whate...

In Docker, an image is a stack of Read-only image layers. We also know that images share layers or other images. My question is about how this sharing mechanism work. Does an image have pointers t...

I am running docker on a Redhat system with devicemapper and thinpool device just as recommended for production systems. Now when I want to reinstall docker I need two steps: 1) remove docker dire...

I just can't create and run new containers in Docker anymore. But in the same time a can run previously created containers. When I try to do something like this: [user@host ~ ] docker run --nam...

I'building a mesosphere infrastructure on AWS instances with 3 master servers (running zookeeper, mesos-master, marathon and haproxy) and N slaves (running mesos-slave and docker). If I run the s...

I have some problem about the storage. The folder /var/lib/docker/devicemapper/ is taking 50% of my storage. In the folder /var/lib/docker/devicemapper/mnt, I have many empty folders. How can I...

What are the implications of exporting /var/lib/docker over NFS? The idea is to store the docker images in a server and export it to hosts which has limited memory to store and run containers. This...

I recently heard (from a RedHat guy) that "direct-LVM"(devicemapper) is the recommended storage-backend for production setups, so I wanted to try that out on a CentOS 7 VM. (where loopback-LVM seem...

I am trying to implement device mapper target by referring to the already existing ones dm-linear, dm-snapshot, dm-cache etc. In my implementation, I need to perform a read/modify/write operation o...