[mythtv-users] warning for anyone with western digital green drives

Mark Lord mythtv at rtr.ca
Fri Jan 6 22:17:08 UTC 2012


On 12-01-06 02:06 PM, jk90090 wrote:
> I've used various WD Green drives in my RAID 1 and RAID 6 config without 
> particular issue.  My Seagate drives are barfing before my WDs are.
> I know all of these manufacturers are setting the maximum response time 
> for 'consumer class' drives for I/O calls to long lengths so RAID 
> controller can get cranky under high loads and timeout the drives from 
> time-to-time.  This is generally a ploy so they can in turn sell 
> 'enterprise' drives instead for those purposes when in reality the 
> mechanics in many cases (but not all) are identical.

No, it's not that.

What they are doing for "RAID" firmware versions is reducing the amount
of time the drive is permitted to spending attempting to recover data
from a big-mangled sector.  The idea is that in a RAID, a good copy of
the data is very likely to exist on one of the other drives, so there's
no point in grinding the entire system to a halt for 30 seconds while
the drive firmware tries its hardest to maybe recover data from the sector.

In a "consumer" situation, things are probably NOT in a RAID, and that
failing sector probably has the only copy in existence of the user's data.
So the drive firmware should re-read many times in hopes of recovering
the data before otherwise giving up.

Different needs.


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