How I put OSX on a disk with badblocks, while avoiding them?
don't tell me to buy an HDD


Buy a new HDD.

Here's why.

First, a bit of history. 

ALL disk drives have bad sectors. Way back in the 1980s drives were simple mechanical devices that came with a bad sector list. Today, the bad sectors are mapped in the drive's firmware. The drive has slightly more storage than advertized and the controller just replaces a bad sector with a spare one. As more sectors read as bad they are also replaced. End result is a drive that appears perfect to the end user.

Your drive has exposed bad sectors, which means the controller has run out of spare sectors to use. This is a serious problem that will not get better. If the cause of the bad sectors was a head crash, the now-damaged head will be slowly scratching up the rest of the drive.

So, your choices are:


get a new drive now, enjoy years of trouble-free service.
don't get a new drive now, have several months of bad performance, data loss, and general unreliability. Get new drive when the current one fails completely.


Laptop-size drives that fit a Mac Mini are available on Amazon for $75 (1Tb Western Digital Black 7200rpm) down to $20 (120Gb chinese whitelabel). Or an SSD for about twice as much per gigabyte.

Depending on your Mini's series replacement difficulty ranges from "tedious" to "challenging". The original ones require 2 big putty knives in addition to the normal screwdrivers, the newer (short, wide, all-aluminium) need a special tool.