
Backblaze statistics: determine the best HDD in the 2nd quarter of 2016
The report first appeared 8 TB HDD

Backblaze released a statistical report on the use of hard drives for the second quarter of 2016. It is noteworthy in that it first appeared data on disks of 8 TB. The manufacturer of these HDDs is Seagate.
The number of hard drives used by the company is constantly growing. In 2013, 27,134 discs worked in the Backblaze data center. As of December 31, 2014, 41,213 disks were operating. In the first quarter of this year - 61 590 HDD. Now the report cited by the company includes data on 68,813 hard drives of various sizes and from different manufacturers.

Notes on the table:
1. For several models, the annual failure rate is 0.00%. They did not have failures in the 1st quarter of 2016;
2. The annual percentage of failure is calculated as follows: ((Failures) / (Days of work / 365)) * 100. In some cases, it is worthwhile to carefully look at the number of failures and days of work to understand why the ratio turned out to be one or another.
The “Drive Days” indicator is calculated quite simply - this is as many days as the disk is in the system in working condition. For example, if the hard drive was installed on July 1, and it failed on August 31, then the “Drive Days” indicator is 62 days with 1 failure in the “overall standings”. The disk can be removed from the system and to replace a larger HDD with no failure. Be that as it may, the number of “Drive Days” is added to the total number, even if there are no failures.
Failing specialists of the company consider disks that do not turn on or are not recognized in the OS, or the disk does not synchronize or does not keep synchronization in the RAID array. Another option is unacceptable SMART statistics.
The data for the first quarter of this year indicated 8 TB drives. But then there were very few of them , only 45 pieces, this is too small a sample to make any conclusion.

Now the company has immediately bought several thousand pieces of such disks (2,700), and the selection is already large enough to draw certain conclusions. This 8 TB HDD model uses the SATA 6 Gb / s interface. The form factor is 3.5 inches. There are 45 new drives in the Storage Pod storage systems, and storage systems are deployed in Backblaze Vaults. The company says that in the third quarter, 8 TB drives will be even larger. According to Backblaze experts, they decided to purchase larger disks in order to increase the efficiency of using the space occupied by storage systems. You can now store double the amount of data in one Storage Pod if you use 8 TB disks instead of 4 TB.
This quarter, it was decided to abandon work with 2 TB HGST drives, whose age reached 64 months. In total, the company's data centers have 85 Storage Pod with 2 TB drives. Replacing a HDD is a gradual process, during which storage systems with such disks will be cleaned several pieces a day. To replace the disconnected systems, connect new ones with larger disks. Now the company has been able to replace half of the 2 TB systems with a Storage Pod with larger hard drives.
Discs from HGST in volumes of 2 and 3 TB proved to be very good at work. The failure rate is only 1.6% and 0.8%, respectively, for disks of the indicated volumes. The manual says that they are even a little sorry for the old systems that have served faithfully for a long time.
And how much data is stored by Backblaze?
It turns out that the amount of information stored in the company's data centers is already 250 petabytes. Of these, 50 petabytes were accumulated in just the last 2 quarters. The company crossed the mark of 250 petabytes in mid-June.

What are the best HDDs?
Model breakdown

Disks used in the company

The company is gradually abandoning Toshiba and Western Digital hard drives, as there were a lot of problems with them . And the point is not in their reliability, but in the fact that Backblaze uses a lot of discs, lots of 5000-10 000 copies are constantly required. Transactions with Western Digital are often frustrated, and Toshiba, according to the company's specialists, does not offer a solution with an optimal price / quality ratio.
8 TB disks are holding up quite well so far, but little time has passed since their use began, so conclusions on their reliability can be made no earlier than a quarter, or even a year.
For reference: Backblaze specializes in online backups. Using the service, users upload backup copies of their data to the cloud in the company's data center.