Re: DO NOT BUY Western Digital "Green" Drives (also present in WD "Elements" external USB cases)
On Sat, 03 Sep 2011, Mike Castle wrote:
> On Sat, Sep 3, 2011 at 1:14 PM, Luke Kenneth Casson Leighton
> <email@example.com> wrote:
> > just a word of warning: on absolutely no account, not for any reason,
> > should you buy WD "Green" drives.
> > i've just spent a hair-raising 6 weeks discovering that these drives,
> > when pushed above a mere 40 Centigrade, become so unstable that they
> > can actually become completely unresponsive, shut down, and leave the
> > linux kernel in a completely unstable state, especially if they are
> > part of a RAID1 mirror.
> For what it's worth, WD _does_ say not to use Green drives in RAID and such.
They do so because the drive can take arbritarily long times to complete a
request when it faces any media issues or firmware snafu's, and most RAID
can't cope well with that (md can, but you *have* to set up the
per-backing-device timeouts properly).
If the drives are dying from overheat, that's something else entirely.
However, do NOT do anything as foolhardy as trusting the firmware on those
devices to actually be able to handle SMART attribute read requests properly
doing intensive IO (or the kernel, or the SATA HBA). Stuff like running
hddtemp once a minute is a very bad idea.
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot