Mikael Abrahamsson wrote:
On Wed, 21 Apr 2010, Bill Davidsen wrote:
I hear this said, but I don't have any data to back it up. Drive
vendors aren't stupid, so if the parking feature is likely to cause
premature failures under warranty, I would expect that the feature
would not be there, or that the drive would be made more robust.
Maybe I have too much faith in greed as a design goal, but I have to
wonder if load cycles are as destructive as seems to be the assumption.
What I think people are worried about is that a drive might have X
load/unload cycles in the data sheet (300k or 600k seem to be normal
figures) and reaching this in 1-2 years of "normal" (according to the
user who is running it 24/7) might be worrying (and understandably so).
Otoh these drives seem to be designed for desktop 8 hour per day use,
so running them as a 24/7 fileserver under linux is not what they were
designed for. I have no idea what will happen when the load/unload
cycles goes over the data sheet number, but my guess is that it was
put there for a reason.
I'd love to find some real data, anecdotal stories about older drives
are not overly helpful. Clearly there is a trade-off between energy
saving, response, and durability, I just don't have any data from a
large population of new (green) drives.
My personal experience from the WD20EADS drives is that around 40% of
them failed within the first year of operation. This is not from a
large population of drives though and wasn't due to load/unload
cycles. I had no problem getting them replaced under warranty, but I'm
running RAID6 nowadays :P
Sorry, you sound like a factory droid. *I* see no reason for early
failure besides cheap mat'ls in construction. Were these assertations
of short life to be true, I would campaign against the drive maker. (I
think that they are just normalizing failure rate against warranty
claims) Buy good stuff. I *wish* I could define the term by mfg. It
seems Seagate, & WD don't hack it. The Japanese drives did, but since
the $ dropped -
One thing seemingly missed is the relationship between storage density
and drive temp.variations.. Hard drive mfgs are going to be in deep
doodoo when the SSD folks get price/perf in the lead lane. This year, I
predict. And maybe another 2 for long term reliability to be in the lead..
I believe that many [most?] RAID users are looking for results (long
term archival) that are not intended in the design.We are about 2
generations away from that being a reality - I think.. For other users,
I would suggest a mirror machine. with both machines being scrubbed
daily, and media being dissimilar in mfg and mfg date.
I can't wait until Neil gets to (has to) play/work with the coming tech.
Neat things are coming.
b-
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