OT - testing HDDs using badblocks command. (final)

[cobaka]

Hello all.

Final, final update: I tested this drive repeatedly with 'badblocks'.
The drive stalled and after that was not detected by GParted.
This drive is now 'in the trash-bin'. Read below if you need to know more, otherwise you may stop here.

First posting:
Recently I purchased two second-hand 500GiB hard drives (Western Digital). SATA, of course.
Naturally I tested them with the Linux command 'badblocks'

The badblocks report has this form: blocks done -- elapsed time (hh:mm:ss) -- ( ##/ ##/ ##) errors.
The numbers (##) are read / write / compare .
For one disk the error numbers are: 1056/0/0 with a final report:
Pass completed. 1057 bad blocks found (1057/0/0)

The second drive (after a single test lasting an hour or so) was 0/0/0

The badblocks command was: badblocks -sv /dev/dsb

Question: How should I understand 1057 'bad' blocks on a 500GiB drive. Does the disk itself 'map out' bad blocks?
Should I trash his drive?
Woof!
собака.

[cobaka]

Update:
In my previous posting errors appeared about 1/2 way thru the test sequence.
I ran a second test: badblocks -wsv -t random /dev/sdb

Here, the test writes random values to each 'block' (sector).
The test is now 80.1% complete - with no errors detected.
I'll continue to test. Go figure!

A more recent update: 100% done, 2355 read errors, 0 write errors, 15 conversion errors. 15:23, local time

собака.