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

[Dale]

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

:-)  :-)