Backblaze, which is a cloud storage company, always keeps recording the Hard Drive Reliability available from different suppliers. The 2015 numbers reveal the success of the 4TB Seagate ST4000DM000.
As, backblaze is well known for updating hard drive statistics with latest data. So, with the end of 2015, their datacenter had 47, 561 spinning hard drive containing customer data. Eliminating drive models less than 45 drives, boot drives and drive in testing systems are publishing data, they publish data on 46,038 hard drives spread across 21 different models, from 1.5TB to 8.0TB in size.
Whole hard drive that has been reviewed are used in the production system in their data center. All drives has been monitored individually along with climate controlled environment. They also said that they had put the available SMART stats reported by each and every drive.
According to them, they had taken a snapshot of each operational hard drive. This snapshot includes basic details of the drive along with the S.M.A.R.T. statistics reported by that drive.
One drive snapshot is one record or row of data. Snapshot of all the drive for a given day are gathered into a file consisting of a row for each active hard drive whose format is a “csv” (Comma Separated Values) file. Every day, this file is named in the format YYYY-MM-DD.csv, for instance, 2013-04-10.csv.
Each file’s first row contain column names and rest are actual data that has been measured or obtained. The columns includes:
- Date : Format of the date file is yyyy-mm-dd .
- Serial Number : It’s a drive serial number assigned by the manufacturer-assigned.
- Model : Drive model number assigned by the manufacturer.
- Capacity : The capacity of the drive(in bytes).
- Failure : Holds “0” if the drive founds to be is OK and contains a “1” if drive has last date and was operational before getting fail.
- 2013-2014 SMART Stats : Contains 80 columns of data, for 40 different SMART stats and that is Raw and Normalized values as reported by the given drive. All that normalized and Raw value is just a number reported by the drive.
- 2015 SMART Stats : It contains 90 columns of data for 45 different SMART stats, that is Raw and Normalized values that has been reported by the given drive. Like above, here also, value is the number reported by the drive.
Here, they uses two SMART stats of particular interest: hours in operation and drive temperature. The SMART 9 property facilitates you to compute the age of the drive, on the other side, SMART 194 property facilitates them determine that all drives are within their acceptable temperature range.
Hard Drive Failure Rates :
Here they starts with comparing the reliability stats of the hard drive for the January-June 2015 period with the stats from 2014:
Trends in Hard Drive Failure Rates :
Table shown below shows the cumulative Hard Drive reliability stats over time.
Failed Hard Drive Definition :
Backblaze has considered three reasons for being a drive to have “failed”:
- Not spinning of the drive or to not connecting to the operating system.
- Not syncing of the drive,. Preferably, not stayed synced in a RAID Array. ( Backblaze Vaults don’t use RAID. Instead of that, they use their open-sourced implementation of Reed-Solomon encoding to replace the function of RAID. And this conclude, these drives are not subject to RAID-sync errors. Stand-alone Storage Pods is only applicable for RAID-sync failures)
- The Smart Stats that has been used by them show values above the thresholds.
Both Seagate and HGST 4GB drives performing well. Actually, 4Gb drives continues with rocking performances. Having a street price of $131.58 each, the Seagate 4TB drive has a current cumulative failure rate of 3.0%. Same on the other side, HGST 4TB drive poses a higher street price of $174.99 with a lower cumulative failure rate of 1.18%. Both Seagate 4TB drive and HGST 4TB drive have been in service for year and currently own 17,000+ and 11,000+ and more respectively. They also has troubles getting the Toshiba drives quoted to them In quantity, however some movements appears on that front. As compare to other drives, Western Digital drives quoted to them at a higher price. Thus, until they get any reasonable number of these drives, they had not recommended either of them. But, for your personal use, you may find them to be fine.
The data is till not firm in case of 6TB drives. However, they manage to buy 450 Western Digital 6TB drives that having 6.2% failure currently while having 8 months in service. But, their failure rate has fluctuated over time from 3.07% to 13.75%. Whereas, 495 6TB Seagate driver poses a lower current failure rate of 3.8% while having in service for less than 6 months. In short, to get a good fix on the rate of failure of these 6TB drives, more time is needed.
If talking about 8TB drives, that they have deployed, they requires more time before recommending anything. Currently, they had 45 HGST 8TB drives(Helium) set up for about one quarter. Drive failure that is certainly not enough to draw any conclusions is the main causes for the current failure rate of 5.3%.
They have on production of 1.5TB and 2.0TB drives that are gradually being replaced with somewhat larger capacity drives. Having average age of over 5 years, Seagate 1.5TB drives has become some of the oldest drives in their data center. It has a failure rate of 10% currently, so it has being replaced first. Exceptionally, HGST 2TB drives have been running. After having service of 4+ years of service, it poses a cumulative failure rate of 1.9%. The HGST drive, model HDS722020ALA330, features an all-star performances, if you’re interested in a 2TB drive. As, they are still available on Amazon for $56.43.
They have replaced nearly all of their Seagate 3TB drives as far as 3TB drives go. If you are interested in getting a 3TB drive, then you can go for HGST 3TB drive (model HDS723030ALA640) as they had a positive experience with it. It has a current failure rate of 1.83% in their environment is. Also, it’s available in stock on Amazon for $110.88. On the other side, The HGST 3TB, ( HDS5C3030ALA630 Model), will be also the good choice, but it’s quantities seem to be limited.