So I have problem.

I run a samba server which host a backup directory to the network for windows backup and clonezilla applications. It's stored on 4.5TB Raid 5 Array, but I also have 3 independent drives using rsync, acting as backup storage devices incase the array fails.

Well one of the 3 drives are full, when I mean full, I mean 100%
The "Backup's" share is the problem. It has more then 2TB of backups from the last 2 years, this stuff is critical to my business but also my family and few of my closest friends.

How I have it setup is the array is mounted as /storage with ext4/ordered_data.
I have three directories in /storage as data1, data2, data3.
The three independent drives are mounted as backup1, backup2, backup3 with ext3/journal_data mode. I use a weekly cronjob to start an rsync operation to backup the data from the array to the independent disks.

Idea was if the raid 5 failed, I would have backups of the entire array. If one of the independent disk failed, I could easily replace the failed disk the same day and initiate a rsync operation.

I need to split the Backup's share and spread it across the three data directories, so that the next rsync operation will correct the space issue on backup1.

Problem is.. I need samba to point to three the directories for the share "Backup's."

This is what I'm thinking is to create a new directory on /storage, then create symbolic links to the split "Backup's" across directories data1,2,3 to that newly created directory then have samba host the newly created directory as "Backup's"

Would this work?

This is the layout.
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda3              72G   19G   50G  27% /
/dev/hda1              99M   38M   57M  40% /boot
tmpfs                 872M     0  872M   0% /dev/shm
/dev/md0              4.5T  2.4T  2.0T  55% /storage
/dev/sdi1             1.8T  1.8T     0 100% /backup1
/dev/sde1             1.4T  255G  1.1T  20% /backup2
/dev/sdf1             1.4T  302G 1004G  24% /backup3
none                  872M  128K  872M   1% /var/lib/xenstored