3.1 NFS

On tarpool, you can export a folder to jd. In other words, make tarpool an NFS server, and make jd an NFS client. On tarpool, a line of /etc/exports may read

/backup/jd          jd(rw,no_root_squash)

This line assumes that the root of jd can be trusted, therefore there is no root squashing. If both tarpool and jd are administered by the same staff, this assumption is usually reasonable.

Because permissions on tarpool are exported to jd, it is rather important to ensure that the folder /backup/jd on tarpool is set to 700. This ensures that this folder is accessible by root on jd. This step is very important, otherwise you can expose the backup of important files to other users on jd!

When it is time to back up files, jd needs to mount the volume remotely using the following command:

mount tarpool:/backup/jd /backup

This command assumes there is a folder /backup on jd to mount the remote file folder. Although unnecesary, it is best to set the permissions of /backup on jd to 700 as well to keep curious users away, and make sure the owner is root.

After this, one can use tar or cpio to archive files on jd to the /backup folder. After the back up process, /backup should be unmounted.