I'm playing with volume containers on boot2docker to run Docker on MacOS X.
boot2docker version
Client version: v1.2.0
Git commit: a551732
I'm trying to perform the backup/restore process which is mentioned in Docker's documentation.
I'm trying to backup a MySQL database which is over 2 GB. When I run the backup command:
docker run --volumes-from data_volume -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /var/lib/mysql
...if fails with this error:
tar: /backup/backup.tar: Wrote only 4096 of 10240 bytes
tar: Error is not recoverable: exiting now
It seems tar is out of disk space. So I got into my container and looked at the host bind mount and its size is 1.8 GB.
docker run -t -i -v $HOME:/demo ubuntu /bin/bash
root@bb3921a48ba4:/# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 19G 8.3G 9.1G 48% /
none 19G 8.3G 9.1G 48% /
tmpfs 1005M 0 1005M 0% /dev
shm 64M 0 64M 0% /dev/shm
/dev/sda1 19G 8.3G 9.1G 48% /etc/hosts
tmpfs 1.8G 1.8G 0 100% /demo
tmpfs 1005M 0 1005M 0% /proc/kcore
You can see that /demo is only 1.8G...
I don't know how to extend this size so I would be able to make large backups...
Any idea? Thanks!
I have this sneaking feeling that you're running out of memory - as 2GB is the default amount of ram we allocate.
Rather than writing to a file, mapped to a virtual filesystem that is attached to your OSX box's FS, I'd suggest running the tar to output to STDOUT, and then pipe that to your local box.
ie
docker run --rm ubuntu tar cf - /etc > test.tar