Instead of hard-deleting a structured record for Bob Smith, can you leave the record intact and scrub it of identifying data so that I don't e.g. break all of the records for orders that Bob Smith made?
The various laws (GPDR, and similar ones in my jurisdiction) abuse the hell out of vague descriptions like "personal identifying data".
For example, scrubbing a customer record of all names, phone numbers, contact info, etc and leaving only the ID in the record still makes it possible to personally identify the person by:
1. Looking through the orders records to build up a profile depending on what they order,
2. Then using the delivery records from the courier company to get an address,
3. Then using existing public information to repopulate all the fields in the customer record.
In any given business, no matter how big or small, simply removing all references to a customers personal information will still leave the customer personally identifiable. This process can even be automated.
GDPR does differentiate between structured data (I believe it uses the term “identifiable records” or similar), and huge heap of unstructured data where an individuals data can’t be quickly retrieved as it’s own atomic unit. With much stricter requirements for anything structured.
So for data on a HDD that could be recovered, but is an unstructured mess. You’re probably ok, as long as you took reasonable steps to protect the data, like full disk encryption (which could occurs below the file system, and thus allow you to recover data deleted from the FS with a full disk scan, as long as you still had the keys). If you just had peoples data unencrypted on a HDD, and didn’t securely erase it before dispose, then that’s probably still a GDPR violation.