Tried searching knowledge-base, college, forums using following search terms: secure erase, erasing, drive wipe, zero-fill, shred and file shredder
Only found information online that eluded to fact that only some NAS makers, and probably only on very expensive enterprise models at that, support secure erase applications. My lower-end Asustor AS6404t does not have an App or built in feature to do this.
I had to turn one of my notebook computers into a Linux machine and let it set for days on end doing nothing but securely erasing my 4TB to 8TB external USB drives and also had to buy a USB to SATA powered adapter as well (not all of them work well, so read reviews carefully before buying one).
I didn’t want to tie up my (home) work-horse computers with securely erasing my old hard drives (now that i bought a good NAS). Seems the point of a NAS is that is should offload a lot of work with all of my drive management for me. It’s essentially a dedicated hard-drive-computer so it's a little sad that i can’t use it to wipe / erase / zero-fill my hard drives
Also took a while to find the best software solution to erasing all of my old disks. None of the Linux tools i tried were very stable or had the features i wanted.
- I wanted something to do random 0’s and 1’s only, on a single pass.
- I also wanted the scrubber to work with 3 or more USB disks at the same time.
- I needed good logging / reporting as well.
- It had to boot direct from a USB drive so i could use it on a small notebook PC without worrying about it running from the installed OS.
The only tool i found that was able to do everything i wanted was active@killdisk:
https://www.killdisk.com/eraser.html
https://www.killdisk.com/killdisk-home.htm
It was a little expensive at $50 for the software, $40 for USB to SATA controller, and $80 for an old Intel i5 laptop at recycling center, but i’ll use it even more, now that i can keep consolidating all of my drives into my new NAS. I’m actually glad i’m not eating up my NAS to do this menial of task work anyway – so it definitely worked out for the best! I sold all of my old HDD"s on eBay and helped keep crappy spinning drives out of the landfill a while longer.
There might be a way to use the Linux Central App (with Debian 10 Desktop) to access local drives on the Asustor NAS - but i couldn't figure it out even with a ticket to Asus support team. At that point you could use the freeware or paid version of Active KillDisk, or other drive scrubber software, and do the job that way. Since i'm a tech at a hospital it was a good training / learning experience anyway.
Hope this helps!
to ADM 5.0 
