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Gerry's questions

Martin Hope
Gerry
Asked: 2015-09-14 19:22:29 +0800 CST
  • 9

I'm using Docker Toolbox on OSX.

I've created a data volume container for storing persistent data: https://docs.docker.com/userguide/dockervolumes/#creating-and-mounting-a-data-volume-container.

I checked that this data is indeed stored on the boot2docker VM (created by docker-machine) and not on the container, so that it will persist. However "docker-machine restart " clears out this custom data on the vm.

I can't find documentation on what is happening. I found one forum post mentioning that data in /var/lib/docker will be preserved, but I could not find any official docs stating that and it also seems strange considering the persistent storage guide above doesn't use this path or even mention that your data will be deleted.

Is this expected and if so is there any official documentation on the correct path to store persistent data?

Edit: Adding example of failing senario

$ docker-machine ssh alt
docker@alt:~$ docker run -v /data:/var/lib/mysql --name mydata busybox sh -c "echo 'hello' > /var/lib/mysql/hello"
docker@alt:~$ docker run --rm --volumes-from mydata busybox sh -c "cat /var/lib/mysql/hello"
hello
docker@alt:~$ exit
$ docker-machine restart alt
Starting VM...
$ docker-machine ssh alt
docker@alt:~$ docker run --rm --volumes-from mydata busybox sh -c "cat /var/lib/mysql/hello"
cat: can't open '/var/lib/mysql/hello': No such file or directory
mac-osx
Martin Hope
Gerry
Asked: 2013-10-21 19:51:18 +0800 CST
  • 8

In the mysqldump docs I see a "--quick" option, however there is no indication as to why somebody would want this disabled. What are the disadvantages to enabling it or why is it even an option? Shouldn't it just be always on?

http://dev.mysql.com/doc/refman/5.7/en/mysqldump.html#option_mysqldump_quick

edit: While it's been made clear to me that it is enabled by default, this isn't too clear the from the official documentation (especially when some samples specify the option: http://dev.mysql.com/doc/refman/5.7/en/copying-databases.html). The table of options does not have a field specifying the defaults and the description of --quick has no note that it's included by --opt. I'll leave the question title as it was so that others looking for the same thing via Google can find the information easily.

mysql