Backblaze, a storage service provider, has just released a popular hard disk reliability statistical report for the second quarter of 2020, covering a total of 142630 mechanical hard disks in the company’s cloud storage ecosystem. These hard disks are distributed in four data centers of backblaze, including 2271 boot disks and 140059 data disks. As of June 30, the reliability statistics of various brands of hard disks running in its data center have been released, which provides us with some opinions on the failure rate of hard disks. < / P > < p > by the end of the second quarter of 2020, backblaze used 140059 hard drives to store customer data. In order to carry out a serious evaluation, at least 60 models (equivalent to only 139867 hard disks) were excluded. < / P > < p > on this basis, the annual failure rate (AFR) of hard disk in the second quarter of 2020 given by backblaze is 0.81%. This is not only down from 1.07% in the first quarter of this year, but also the lowest since the beginning of the 2013 report. < / P > < p > at the same time, this is the first time that backblaze gets less than 1% in quarterly statistics. As a comparison, the quarterly AFR in the same period of last year (2019 Q2) is 1.8%. < / P > < p > although the total data of Toshiba’s 4tb HDD is less than 10000 days, since the fourth quarter of 2018, Toshiba has continuously given zero failure results in the service time equivalent to 54054 days. < / P > < p > another 192 HDDs were not included in the quarterly statistical list because the sample size was less than 60. This includes 20 Toshiba 16TB (mg08aca16ta), which is waiting to pass the rigorous inspection of backblaze. < / P > < p > at the same time, more than 12063 new hard disks were added to backblaze’s data center in the quarter, with the 1960 removed hard disks removed, a net increase of 10103. < / P > < p > (1) every quarter, backblaze will count the annual failure rate (AFR) of HDD in its data center from the beginning, but the hard disk for boot and test is not included in the statistics. < / P > < p > (2) from the third quarter of 2017 to the third quarter of 2018, Toshiba hard disk has maintained the excellent performance of zero failure rate, but the sample size is too small. During this period, no more than 231 HDDs have been in service. < / P > < p > (3) starting from the second quarter of 2019, the N / a value of Western data indicates that during this period, backblaze used zero block WDC drive in its system to store customer data, and did not consider the new model of hgst renamed and replaced. < / P > < p > (2) Toshiba’s situation is similar to that of western mathematics. For most of the time during this period, Toshiba HDD was too small to draw any reasonable conclusions. But from the fourth quarter of 2019, its reliability is beginning to become more assured. < p > < p > (3) the AFR of Seagate HDD has increased steadily for some time, but the performance in the last two quarters is relatively friendly. The data of 0.90% is the lowest since backblaze started statistics in 2013, and its performance in the next few months is more to be expected.