I wonder if your links are breaking because the device letters (/dev/sdb, /dev/sdc, and so on) are not always the same, as sometimes happens with external drives. Mounting by label or by UUID may be part of the solution.
I have two external USB drives mounted by UUID. I found the UUIDs by looking in /dev/disk/by-uuid:
tony@peshobi:~> cd /dev/disk/by-uuid
tony@peshobi:/dev/disk/by-uuid> ls -1
tony@peshobi:/dev/disk/by-uuid> file *
003c0b79-e7d6-4af4-816b-fa34481ac327: symbolic link to `../../sdb1'
0993-CB32: symbolic link to `../../sdc1'
80ca8e57-c355-4416-8216-b9e2223c0019: symbolic link to `../../sda1'
d8c6a024-1249-42d9-a5e0-d2d1f47f731d: symbolic link to `../../sda2'
fef42ba4-9cb5-47e1-bd6b-ad1dc80e9841: symbolic link to `../../sda3'
My fstab, for example, includes these two lines:
UUID=003c0b79-e7d6-4af4-816b-fa34481ac327 /media/max1tb ext4 defaults 0 0
UUID=0993-CB32 /media/sea2tb vfat users,gid=users,umask=0002,utf8=true,nofail 0 0
Mounting by label is another option, but I have not tried it.