In Blaskblaze they have tested the reliability of the most used hard drives during the year 2014, in a test with 34 881 discs, which store over 100Pbytes of data being continuously tracked to know which are more reliable and which should be replaced .
The loss of a disk drive in Backblaze is not a big deal, each disk containing files, has been cloned in several units in the data center, so when a drive fails, it is replaced promptly and the data is restored from the copy created from previously, but still, they avoid the defective units, because the replacement thereof, costs money.
They closely monitor units to know what state they are and if they are doing their job well and which are not, to assist us in the selection of new units to purchase when next replacement is made.
The good news is that figure today is much like the one we got in January with good results, since most of the units continue to perform with good form and it’s nice because it means that they are stable.
The surprisingly bad news is that the Seagate 3TB drives are failing a lot, with a failure rate of around 9% to 15% and 3TB drives from Western Digital also going to failure at a rate that increases from 4% to 7%.
In the chart below, you can see the gray bars, representing the failure rates of late 2013, and the color bars are the failure rates of all data from the end of June 2014.
It can be seen as all Hitachi, Seagate 1.5TB and 4TB drives and Western Digital 1TB disks continue to operate normally while 3TB drives, both Seagate and Western Digital, decay.
What is the possible cause of this?
One possible cause is that these units are not as well adapted to the data center environment, or when removing them from external USB boxes is causing loss of performance and to find the main cause, they’re still analyzing reports to inform future development of these units.
Should we change the units in the businesses?
Assuming you continue to see rates higher failure by 15% in units, it is no longer a completely reliable replacement unit, with an equal from the manufacturer, but maybe if it is, if the replacement of a unit is designed for businesses.
A business unit costs about 200 dollars, while the units designed for ordinary users, less than 100 dollars, although both would be accompanied by a three years guarantee, as stipulated by the manufacturer, but if we rely on the numbers, we see the guarantee time, in this case, is irrelevant, since 15% of units designed for desktops are deficient, with a large number of units affected, compared to units designed for businesses with a failure rate of 0% obtaining a balance of about 10 years of use, it is more of runtime, we get from desktop unit.
Detailed Reliability of hard drive models
In the following table, we can see, in detail, the tested units, average usage and failure rate, including all drive models available, about 200, and a pair of models, new in Backblaze which show a rate "n / a", because at the moment, the data is not enough to begin to draw conclusions on its reliability.
While the failure rate in the 3TB drives, Seagate and Western Digital, continues to increase, the vast majority of the remaining units intended for the user, continue with good performance, being a cost effective way to provide unlimited online backup at a good price.