30TB UnRaid Server

That seller will have a tough time at that price with any knowledgeable buyer.

You could build a NEW 30TB server in a mini-ITX case with 6 6TB drives that would use FAR less power; run faster; and have 3 year warranties on the drives for ~ $2300 ... a bit more than half of what he's asking.

Yeah...that thing will never sell at that price.  Plus...check out those drive temps!  No, thanks!

The google study http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en//archive/disk_failures.pdf found that:

We first look at the correlation between average temperature during the observation period and failure. Figure 4 shows the distribution of drives with average temperature in increments of one degree and the corresponding annualized failure rates. The figure shows that failures do not increase when the average temperature increases. In fact, there is a clear trend showing that lower temperatures are associated with higher failure rates. Only at very high temperatures is there a slight reversal of this trend.

yea, hitachi drives tend to run hotter than most and they have the lowest failure rate.

The temps aren't bad ... mostly upper 30's (displayed in Fahrenheit).

But it's a 2-year old build, and you can build one with NEW technology using faster, more reliable disks, with a much faster CPU that uses far less power, for just over half of what's being asked.

It's certainly not a bad build ... just over-priced.

The google study http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en//archive/disk_failures.pdf found that:

We first look at the correlation between average temperature during the observation period and failure. Figure 4 shows the distribution of drives with average temperature in increments of one degree and the corresponding annualized failure rates. The figure shows that failures do not increase when the average temperature increases. In fact, there is a clear trend showing that lower temperatures are associated with higher failure rates. Only at very high temperatures is there a slight reversal of this trend.

The figure shows that failures do not increase when the average temperature increases.

When questioned about this, the author correctly responded that the statement is correct, but often misunderstood. The statement can be rewritten as ... failures do not decrease when the average temperature decreases. In this rewrite, some can see the finding more clearly. The relationship between temperature and failure is not linear. Failures increase at both higher and lower temperatures.

Short form;

Colder is not better.

Colder is not better.

Note that the finding in the Google study that "... there is a clear trend showing that lower temperatures are associated with higher failure rates ..." is almost certainly due to excessive cooling of the drives, which cause far more thermal contraction and expansion of the platters when they heat up during periods of heavy use.

But it IS important that you have ADEQUATE cooling for your drives to keep them at a REASONABLE temperature.  For modern hard drives, that's typically in the mid-30's, climbing a few degrees during periods of heavy use (in the UnRAID context, that would be parity checks).

One final thought:  the study is 7 years old ... doesn't mean it's not still relevant, but it does mean it didn't include any of the modern NAS drives that many folks use today, which are inherently designed to run cooler than previous generations.

STP is 32ºC and SATP is 25ºC. Usually, things are tested using this temperatures as reference.

Very low and very high temperatures are equally bad. A comfortable temperature for HDD is at a delta of 10~20ºC  from those temperatures. More or less can shorten the lifespan. Most manufacturers warranties drives at 55ºC at most.

Colder is not better.

 

Note that the finding in the Google study that "... there is a clear trend showing that lower temperatures are associated with higher failure rates ..." is almost certainly due to excessive cooling of the drives, which cause far more thermal contraction and expansion of the platters when they heat up during periods of heavy use.

 

But it IS important that you have ADEQUATE cooling for your drives to keep them at a REASONABLE temperature.  For modern hard drives, that's typically in the mid-30's, climbing a few degrees during periods of heavy use (in the UnRAID context, that would be parity checks).

 

One final thought:  the study is 7 years old ... doesn't mean it's not still relevant, but it does mean it didn't include any of the modern NAS drives that many folks use today, which are inherently designed to run cooler than previous generations.

Yes, proper cooling is very important. Proper cooling includes not only avoiding highs and lows, but also keeping the drive at a consistent temperature. The typical external USB clam is the best example I have of a really poor cooling solution. For my storage, the goal is to keep drives at 38 +/- 2 degrees across all workloads using 30+ ambient air supply. This task is more difficult with some of the newest drives.

The modern drives are designed to use less power, which means generate less heat. Which is your "run cooler". They are actually designed to operate at the same temperatures, sometimes a bit wider range.