SuperMicro H8SSL-i (ServerWorks HT1000) -- providing technical information

[Mark Hahn]

> I've shown specification sheets of drives with commodity
> capacities (100-400GB) at 1.0M hours MTBF like the Seagate
> NL35 and Western Digital Caviar RE, which match the exact
> capacity/performance specifications as the Seagate Barracuda
> 7200.8 and Western Digital Caviar SE, respectively.  Anyone

arrg!  this is the sort of thing that gets my goat - you claim 
that if the capacity and performance numbers match, then the only
difference between the drives must be some sort of "enterprise"
testing.  but without hard facts from the vendor, this is just 
speculation on your part.  sure, it could make sense, and might 
even make Occam happy.  but not QED, still speculation.

> can do further research on the enterprise capacities
> (18-146GB) and find 1.4M hours MTBF.

translation: some disks have MTBF of X and capacity of C.
this other disk has capacity C, therefore it has MTBF of X.

> altogether.  But if the "enterprise" versions of commodity
> capacity (100-400GB) drives are only 1.0M hours MTBF, you can
> be rest assured the OEM/desktop grades are well below that. 

why does "rest assured" always mean "I say"?

> Going back to the 50,000 restarts and 8 hours/day, maybe 14
> hours/day (0.7M hours MTBF), maximum.

8, 14, who's counting?  do you have any real backup for the claim
(afaikt) that reliability is strictly a function of power cycles?

what if you put a "desktop" drive into a nice rack-mounted, UPS-protected,
machineroom at a constant 20C with great airflow?  I've got a bunch of 
servers (netboot but swap and /tmp on local disks) that have been in 
use for ~3 years and smartctl tells me the disks have seen ~100 
power cycles.

> support RHEL and sell some with SLAs, right? ;-), I know _no_
> HD manufacturer/vendor that will warranty such OEM/desktop
> grade drives when they know they will go in a 24x7 system. 

warranties typically just say something weaselish like "does not cover
abuse".  how would a vendor refuse warranty replacement because of 24x7?
would they just run SMART and divide POH by power cycle count?

oh, no!  I've abused node2's disk by averaging 289 hours per cycle!
(interestingly, current temp is 26C, lifetime min/max is 13/36.)

> belief that I acquire everything from my rectum.  I know it
> takes years to trust what comes from someone, and I'm willing
> to spend years earning that trust.  ;->

so far, I'm not sure you've done anything to earn anyone's trust on,
for instance, the 50,000 * 8 hours => 400Khour MTBF assertion.
repeating it for years won't help...