You need a SAS HBA. Then use sg_sanitize from sg3_utils package.
sg_sanitize --block /dev/sdX
Overwrite with given pattern:
sg_sanitize --overwrite --pattern=rand.img /dev/sdX
If you only have a RAID controller, than you can create a RAID volume and just fill it with zeroes or some random pattern (see scrub).
When using any SFP/SFP+/QSFP/... port you need to make sure that the plugged module is compatible with the port. A physical fit is not enough. Some devices only accept modules branded to the vendor. Sometimes appropriate port configuration is required as well.
plug the SFP+ DAC to an SFP+ port, not a QSFP one
buy a QSFP-to-SFP+ fanout