Is disk really bad if mkfs.ext4 -c -c reports errors?

Liam Proven lproven at
Wed Jan 11 16:31:51 UTC 2017

On 11 January 2017 at 17:21, Chris Green <cl at> wrote:
> Which says it's OK, but it doesn't appear to be OK.

The only thing that we can say for sure is that the disk has a large
number of bad blocks. That is a _very_ bad sign.

The fact that it "thinks" it's fine is irrelevant. Ignore it.

The type or colour of drive cable is irrelevant. The firmware level on
drive or motherboard is irrelevant. These are all things to look after
and be sure are good, but *none of them cause bad blocks.*

One thing causes bad blocks: failure of the magnetic medium on the
surface of the disk.

It's damaged. Throw it out and replace it. You've been formatting it
so there's nothing on it. Recycle it.

In the dawn of the PC era, there was a virus that simulated bad blocks:

It's from 24 years ago. It's from before LBA and EIDE, let alone SATA,
and it wouldn't infect a Linux system anyway. Mind you, Linux was on
version 0.3 back then.

And the "bad blocks" disappeared if you booted off clean media and
reformatted. Which you have done.

*It is not that.*

*It is a dead disk.*

Forget about SMART. The disk is junk. Let it go.

If you have a need for a scratch disk, one where you can afford to
lose everything on it with no warning and no problem, then you can use
it for that. Of course, it might destroy the document you're working
on if a TEMP file goes bad, or crash the whole system, but you might
be really desperate for space.

If the drive is new enough, of course, ask for a warranty replacement.

Liam Proven • Profile:
Email: lproven at • Google Mail/Talk/Plus: lproven at
Twitter/Facebook/Flickr: lproven • Skype/LinkedIn/AIM/Yahoo: liamproven
UK: +44 7939-087884 • ČR/WhatsApp/Telegram/Signal: +420 702 829 053

More information about the ubuntu-users mailing list