From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roman Mamedov <rm@romanrm.net>
Subject: Re: When do you replace old hard drives in a raid6?
Date: Wed, 9 Mar 2016 11:59:05 +0500
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To: Mikael Abrahamsson <swmike@swm.pp.se>
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On Wed, 9 Mar 2016 07:43:16 +0100 (CET)
Mikael Abrahamsson <swmike@swm.pp.se> wrote:

> I had very high failure rates of the early 2TB WD Greens, but I still hav=
e=20
> some WD20EARS and WD20EADS that are alive after 58k hours.

In my experience a major cause for the WD failures is that they develop rust
on the PCB contacts which connect to the drive insides, see e.g.:
http://ods.com.ua/win/rus/other/hdd/2/wd_cont2.jpg
http://www.chipmaker.ru/uploads/monthly_12_2013/post/image/post-7336-020632=
100%201388236036.jpg
and: https://www.youtube.com/watch?v=3DtDTt_yjYYQ8

If such WD drive has just developed several unreadable sectors, this often =
can
be solved by checking and cleaning those contacts, then overwriting the who=
le
drive with zeroes (or well, with whatever you want, the point is to rewrite
all the "badly written" areas), then it will likely work fine for years aft=
er
that.

> One of the slightly lower power on time ones has a scary load cycle count=
=20
> though:
>=20
> Device Model:     WDC WD20EARS-00S8B1
>    9 Power_On_Hours          0x0032   033   033   000    Old_age   Always=
       -       49255
> 193 Load_Cycle_Count        0x0032   001   001   000    Old_age   Always =
      -       1317839

This can be disabled:
http://www.storagereview.com/how_to_stop_excessive_load_cycles_on_the_weste=
rn_digital_2tb_caviar_green_wd20ears_with_wdidle3
http://idle3-tools.sourceforge.net/

--=20
With respect,
Roman

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