kotovalexarian-likes-github/moby--moby
1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
Code Releases Activity

docs: modifying volumes guide to remove ambiguity. Signed-off-by: Andre Granovsky <robotciti@live.com>

Browse source 
Adjusted as per comment.
Rebase and squash by moxigirl

Signed-off-by: Andre Granovsky <robotciti@live.com>
This commit is contained in:
Andre Granovsky 2015-10-28 17:14:49 -04:00 committed by Mary Anthony
parent 92487d7fb4
commit be2152116c
1 changed files with 11 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
docs/userguide/dockervolumes.md
View file

@ -200,30 +200,30 @@ Let's create a new named container with a volume to share.
While this container doesn't run an application, it reuses the `training/postgres`
image so that all containers are using layers in common, saving disk space.
$ docker create -v /dbdata --name dbdata training/postgres /bin/true
$ docker create -v /dbdata --name dbstore training/postgres /bin/true
You can then use the `--volumes-from` flag to mount the `/dbdata` volume in another container.
$ docker run -d --volumes-from dbdata --name db1 training/postgres
$ docker run -d --volumes-from dbstore --name db1 training/postgres
And another:
$ docker run -d --volumes-from dbdata --name db2 training/postgres
$ docker run -d --volumes-from dbstore --name db2 training/postgres
In this case, if the `postgres` image contained a directory called `/dbdata`
then mounting the volumes from the `dbdata` container hides the
then mounting the volumes from the `dbstore` container hides the
`/dbdata` files from the `postgres` image. The result is only the files
from the `dbdata` container are visible.
from the `dbstore` container are visible.
You can use multiple `--volumes-from` parameters to bring together multiple data
volumes from multiple containers.
You can also extend the chain by mounting the volume that came from the
`dbdata` container in yet another container via the `db1` or `db2` containers.
`dbstore` container in yet another container via the `db1` or `db2` containers.
$ docker run -d --name db3 --volumes-from db1 training/postgres
If you remove containers that mount volumes, including the initial `dbdata`
If you remove containers that mount volumes, including the initial `dbstore`
container, or the subsequent containers `db1` and `db2`, the volumes will not
be deleted. To delete the volume from disk, you must explicitly call
`docker rm -v` against the last container with a reference to the volume. This
@ -244,10 +244,10 @@ backups, restores or migrations. We do this by using the
`--volumes-from` flag to create a new container that mounts that volume,
like so:
$ docker run --volumes-from dbdata -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata
$ docker run --volumes-from dbstore -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata
Here we've launched a new container and mounted the volume from the
`dbdata` container. We've then mounted a local host directory as
`dbstore` container. We've then mounted a local host directory as
`/backup`. Finally, we've passed a command that uses `tar` to backup the
contents of the `dbdata` volume to a `backup.tar` file inside our
`/backup` directory. When the command completes and the container stops
@ -256,11 +256,11 @@ we'll be left with a backup of our `dbdata` volume.
You could then restore it to the same container, or another that you've made
elsewhere. Create a new container.
$ docker run -v /dbdata --name dbdata2 ubuntu /bin/bash
$ docker run -v /dbdata --name dbstore2 ubuntu /bin/bash
Then un-tar the backup file in the new container's data volume.
$ docker run --volumes-from dbdata2 -v $(pwd):/backup ubuntu cd /dbdata && tar xvf /backup/backup.tar
$ docker run --volumes-from dbstore2 -v $(pwd):/backup ubuntu cd /dbdata && tar xvf /backup/backup.tar
You can use the techniques above to automate backup, migration and
restore testing using your preferred tools.