Welcome to the Backblaze
Hard Drive Data and Stats
Since 2013, Backblaze has published statistics and insights based on the hard drives in our data center. You'll find links to those reports below. We also publish the data underlying these reports, so that anyone can reproduce them. You'll find an overview of this data and the download links further down this page.

Hard Drive Reliability Statistics

Title Published
Hard Drive Stats for Q3 2017 Q4 2017
Hard Drive Stats for Q2 2017 Q3 2017
Hard Drive Stats for Q1 2017 Q2 2017
Backblaze Hard Drive Stats for 2016 Q1 2017
Hard Drive Stats for Q3 2016: Less is More! Q4 2016
Hard Drive Stats for Q2 2016 Q3 2016
One Billion Drive Hours and Counting: Q1 2016 Hard Drive Stats Q2 2016
Hard Drive Reliability Review for 2015 Q1 2016
What Can 49,056 Hard Drives Tell Us? Hard Drive Reliability Stats for Q3 2015 Q4 2015
Hard Drive Reliability Stats for Q2 2015 Q3 2015
Hard Drive Reliability Stats for Q1 2015 Q2 2015
What is the Best Hard Drive? Q1 2015
Hard Drive Reliability Update Q3 2014
What Hard Drive Should I Buy? Q1 2014
How Long Do Disk Drives Last? Q4 2013

Hard Drive Reviews and Analysis

Yes, Backblaze Just Ordered 100 Petabytes of Hard Drives October 2017
Hard Drive Cost Per Gigabyte July 2017
What SMART Stats Tell Us About Hard Drives October 2016
HGST 8TB Drives – Helium Makes Them Fly June 2015
A Look at Backblaze's Toshiba Hard Drives May 2015
Reliability Data Set For 41,000 Hard Drives Now Open Source February 2015
Our 6 TB Hard Drive Face-Off December 2014
Hard Drive SMART Stats November 2014
Hard Drive Temperature – Does it Matter? May 2014
Enterprise Drives: Fact or Fiction? December 2013

Overview of the Hard Drive Data

Each day in the Backblaze data center, we take a snapshot of each operational hard drive. This snapshot includes basic drive information along with the S.M.A.R.T. statistics reported by that drive. The daily snapshot of one drive is one record or row of data. All of the drive snapshots for a given day are collected into a file consisting of a row for each active hard drive. The format of this file is a "csv" (Comma Separated Values) file. Each day this file is named in the format YYYY-MM-DD.csv, for example, 2013-04-10.csv.

The first row of the each file contains the column names, the remaining rows are the actual data. The columns are as follows:

Helpful Hints and Caveats

The 2015 versus the 2013-14 Schema
For 2015 we began tracking 5 additional SMART attributes, meaning there are 10 additional fields in the 2015 schema. The new SMART attributes being collected for 2015 are the raw and normalized values for: smart_22, smart_220, smart_222, smart_224, and smart_226.

Blank Fields
The daily snapshots record the SMART stats information reported by the drive. Since most drives do not report values for all SMART stats, there are blank fields in every record. Also, different drives may report different stats based on their model and/or manufacturer. 

Inconsistent Fields
Reported stats for the same SMART stat can vary in meaning based on the drive manufacturer and the drive model. Make sure you are comparing apples-to-apples as drive manufacturers don't generally disclose what their specific numbers mean. 

Out-of-Bounds Values
The values in the files are the values reported by the drives. Sometimes, those values are out of whack. For example, in a few cases the RAW value of SMART 9 (Drive life in hours) reported a value that would make a drive 10+ years old, which was not possible. In other words, it’s a good idea to have bounds checks when you process the data. 

The Number of Drives Will Change
When a drive fails, the "Failure" field is set to "1" on the day it fails. The next day, the drive is removed from the list and is no longer counted, reducing the overall number of drives. On the other hand, new drives are added on a regular basis increasing the overall number of drives. In other words, count the number of drives each day. 

Computing Drive Days
Each day a drive is listed in a daily snapshot file it counts as one drive day. For example, if there are 35,000 drives listed in a daily snapshot file that equals 35,000 drive days. In the docs.zip file you can download below, you’ll find a PDF file named “computing_failure_rates.pdf” which describes how we compute drive days, drive years, and drive failures rates. 

Drive Age
As noted, the RAW value of SMART 9 is the number of hours a drive has been in service up to that point. To determine the drive’s age in days, you divide the reported number by 24. 

Missing Data
In Q1 2017, the SMART stats for some of the hard drives during the period of January 28 thru 31, 2017 were not recorded. On February 1, 2017 complete reporting resumed. While this had no effect on the how we use the data, it may, depending on how you use the data, effect your efforts.

How You Can Use the Data

You can download and use this data for free for your own purpose, all we ask is three things 1) you cite Backblaze as the source if you use the data, 2) you accept that you are solely responsible for how you use the data, and 3) you do not sell this data to anyone, it is free.

The Raw Hard Drive Test Data

Hopefully the information above has provided you with the information you need to access and use the hard drive data we have collected. Here is the data: 

2013 Docs and Data
2013_docs.zip - 77.2 KB ZIP file, 111 KB on disk, 5 files.
2013_data.zip - 81.2 MB ZIP file, 775.2 MB on disk, 266 files.

2014 Docs and Data
2014_docs.zip - 77.5 KB ZIP file, 115 KB on disk, 5 files.
2014_data.zip - 587.3 MB ZIP file, 3.02 GB on disk, 365 files.

2015 Docs and Data
2015_docs.zip - 77.6 KB ZIP file, 115 KB on disk, 5 files.
2015_data.zip - 842.9 MB ZIP file, 4.5 GB on disk, 365 files.

2016 - Docs and Data
Q1_2016_docs.zip – 78 KB ZIP file, 106 KB on disk, 5 files
Q1_2016_data.zip – 270.3 MB ZIP file, 1.42 GB on disk, 92 files.

Q2_2016_docs.zip – 78 KB ZIP file, 106 KB on disk, 5 files
Q2_2016_data.zip – 292.4 MB ZIP file, 1.55 GB on disk, 91 files.

Q3_2016_docs.zip – 78 KB ZIP file, 106 KB on disk, 5 files
Q3_2016_data.zip – 322.4 MB ZIP file, 1.68 GB on disk, 92 files.

Q4_2016_docs.zip – 78 KB ZIP file, 98 KB on disk, 5 files
Q4_2016_data.zip – 336.9 MB ZIP file, 1.73 GB on disk, 92 files.

2017 - Docs and Data
docs_Q1_2017.zip – 78 KB ZIP file, 106 KB on disk, 6 files
data_Q1_2017.zip – 338.8 MB ZIP file, 1.74 GB on disk, 91 files.

docs_Q2_2017.zip – 78 KB ZIP file, 90 KB on disk, 5 files
data_Q2_2017.zip – 386.7 MB ZIP file, 1.99 GB on disk, 91 files.

docs_Q3_2017.zip – 78 KB ZIP file, 106 KB on disk, 5 files
data_Q3_2017.zip – 425.7 MB ZIP file, 2.13 GB on disk, 91 files.

docs_Q4_2017.zip – 78 KB ZIP file, 106 KB on disk, 5 files
data_Q4_2017.zip – 465.2 MB ZIP file, 2.22 GB on disk, 92 files.

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