Re: [gentoo-user] Testing a used hard drive to make SURE it is good.

[Mark Knecht]

On Mon, Jun 15, 2020 at 12:37 PM Dale <rdalek1967@×××××.com> wrote:
>
> Howdy,
>
> I finally bought a 8TB drive.  It is used but they claim only a short
duration.  Still, I want to test it to be sure it is in grade A shape
before putting a lot of data on it and depending on it.  I am familiar with
some tools already.  I know about SMART but it is not always 100%.  It
seems to catch most problems but not all.  I'm familiar with dd and writing
all zeores or random to it to see if it can in fact write to all the parts
of the drive but it is slow. It can take a long time to write and fill up a
8TB drive. Days maybe??  I googled and found a new tool but not sure how
accurate it is since I've never used it before.  The command is badblocks.
It is installed on my system so I'm just curious as to what it will catch
that others won't.  Is it fast or slow like dd?
>
> I plan to run the SMART test anyway.  It'll take several hours but I'd
like to run some other test to catch errors that SMART may miss.  If there
is such a tool that does that.  If you bought a used drive, what would you
run other than the long version of SMART and its test?  Would you spend the
time to dd the whole drive?  Would badblocks be a better tool?  Is there
another better tool for this?
>
> While I'm at it, when running dd, I have zero and random in /dev.  Where
does a person obtain a one?  In other words, I can write all zeros, I can
write all random but I can't write all ones since it isn't in /dev.  Does
that even exist?  Can I create it myself somehow?  Can I download it or
install it somehow?  I been curious about that for a good long while now.
I just never remember to ask.
>
> When I add this 8TB drive to /home, I'll have 14TBs of space.  If I leave
the 3TB drive in instead of swapping it out, I could have about 17TBs of
space.  O_O
>
> Thanks to all.
>
> Dale
>
> :-)  :-)

The SMART test, long version, will do a very reasonable job catching
problems. Run it 2 or 3 times if it makes you feel better.

Chris's suggestion about Spinrite is another option but it is slow, slow,
slow. Might take you weeks? On a drive that large if it worked at all.

As an aside, but important, I fear that you're possibly falling into the
trap most of us do at home. Please don't. Once you have 17TB of space on
your system how are you planning on doing your weekly backups? Do you have
17TB+ on an external drive or system? Will you back up to BlueRay discs or
something like that?

Mark