Post Syndicated from original https://www.backblaze.com/blog/backblaze-hard-drive-stats-for-2020/

In 2020, Backblaze added 39,792 hard drives and as of December 31, 2020 we had 165,530 drives under management. Of that number, there were 3,000 boot drives and 162,530 data drives. We will discuss the boot drives later in this report, but first we’ll focus on the hard drive failure rates for the data drive models in operation in our data centers as of the end of December. In addition, we’ll welcome back Western Digital to the farm and get a look at our nascent 16TB and 18TB drives. Along the way, we’ll share observations and insights on the data presented and as always, we look forward to you doing the same in the comments.

2020 Hard Drive Failure Rates

At the end of 2020, Backblaze was monitoring 162,530 hard drives used to store data. For our evaluation, we remove from consideration 231 drives which were used for testing purposes and those drive models for which we did not have at least 60 drives. This leaves us with 162,299 hard drives in 2020, as listed below.

Observations

The 231 drives not included in the list above were either used for testing or did not have at least 60 drives of the same model at any time during the year. The data for all drives, data drives, boot drives, etc., is available for download on the Hard Drive Test Data webpage.

For drives which have less than 250,000 drive days, any conclusions about drive failure rates are not justified. There is not enough data over the year-long period to reach any conclusions. We present the models with less than 250,000 drive days for completeness only.

For drive models with over 250,000 drive days over the course of 2020, the Seagate 6TB drive (model: ST6000DX000) leads the way with a 0.23% annualized failure rate (AFR). This model was also the oldest, in average age, of all the drives listed. The 6TB Seagate model was followed closely by the perennial contenders from HGST: the 4TB drive (model: HMS5C4040ALE640) at 0.27%, the 4TB drive (model: HMS5C4040BLE640), at 0.27%, the 8TB drive (model: HUH728080ALE600) at 0.29%, and the 12TB drive (model: HUH721212ALE600) at 0.31%.

The AFR for 2020 for all drive models was 0.93%, which was less than half the AFR for 2019. We’ll discuss that later in this report.

What’s New for 2020

We had a goal at the beginning of 2020 to diversify the number of drive models we qualified for use in our data centers. To that end, we qualified nine new drives models during the year, as shown below.

Actually, there were two additional hard drive models which were new to our farm in 2020: the 16TB Seagate drive (model: ST16000NM005G) with 26 drives, and the 16TB Toshiba drive (model: MG08ACA16TA) with 40 drives. Each fell below our 60-drive threshold and were not listed.

Drive Diversity

The goal of qualifying additional drive models proved to be prophetic in 2020, as the effects of Covid-19 began to creep into the world economy in March 2020. By that time we were well on our way towards our goal and while being less of a creative solution than drive farming, drive model diversification was one of the tactics we used to manage our supply chain through the manufacturing and shipping delays prevalent in the first several months of the pandemic.

Western Digital Returns

The last time a Western Digital (WDC) drive model was listed in our report was Q2 2019. There are still three 6TB WDC drives in service and 261 WDC boot drives, but neither are listed in our reports, so no WDC drives—until now. In Q4 a total of 6,002 of these 14TB drives (model: WUH721414ALE6L4) were installed and were operational as of December 31^st.

These drives obviously share their lineage with the HGST drives, but they report their manufacturer as WDC versus HGST. The model numbers are similar with the first three characters changing from HUH to WUH and the last three characters changing from 604, for example, to 6L4. We don’t know the significance of that change, perhaps it is the factory location, a firmware version, or some other designation. If you know, let everyone know in the comments. As with all of the major drive manufacturers, the model number carries patterned information relating to each drive model and is not randomly generated, so the 6L4 string would appear to mean something useful.

WDC is back with a splash, as the AFR for this drive model is just 0.16%—that’s with 6,002 drives installed, but only for 1.7 months on average. Still, with only one failure during that time, they are off to a great start. We are looking forward to seeing how they perform over the coming months.

New Models From Seagate

There are six Seagate drive models that were new to our farm in 2020. Five of these models are listed in the table above and one model had only 26 drives, so it was not listed. These drives ranged in size from 12TB to 18TB and were used for both migration replacements as well as new storage. As a group, they totaled 13,596 drives and amassed 1,783,166 drive days with just 46 failures for an AFR of 0.94%.

Toshiba Delivers More Zeros

The new Toshiba 14TB drive (model: MG07ACA14TA) and the new Toshiba 16TB (model: MG08ACA16TEY) were introduced to our data centers in 2020 and they are putting up zeros, as in zero failures. While each drive model has only been installed for about two months, they are off to a great start.

Comparing Hard Drive Stats for 2018, 2019, and 2020

The chart below compares the AFR for each of the last three years. The data for each year is inclusive of that year only and for the drive models present at the end of each year.

The Annualized Failure Rate for 2020 Is Way Down

The AFR for 2020 dropped below 1% down to 0.93%. In 2019, it stood at 1.89%. That’s over a 50% drop year over year. So why was the 2020 AFR so low? The answer: It was a group effort. To start, the older drives: 4TB, 6TB, 8TB, and 10TB drives as a group were significantly better in 2020, decreasing from a 1.35% AFR in 2019 to a 0.96% AFR in 2020. At the other end of the size spectrum, we added over 30,000 larger drives: 14TB, 16TB, and 18TB, which as a group recorded an AFR of 0.89% for 2020. Finally, the 12TB drives as a group had a 2020 AFR of 0.98%. In other words, whether a drive was old or new, or big or small, they performed well in our environment in 2020.

Lifetime Hard Drive Stats

The chart below shows the lifetime annualized failure rates of all of the drives models in production as of December 31, 2020.

AFR and Confidence Intervals

Confidence intervals give you a sense of the usefulness of the corresponding AFR value. A narrow confidence interval range is better than a wider range, with a very wide range meaning the corresponding AFR value is not statistically useful. For example, the confidence interval for the 18TB Seagate drives (model: ST18000NM000J) ranges from 1.5% to 45.8%. This is very wide and one should conclude that the corresponding 12.54% AFR is not a true measure of the failure rate of this drive model. More data is needed. On the other hand, when we look at the 14TB Toshiba drive (model: MG07ACA14TA), the range is from 0.7% to 1.1% which is fairly narrow, and our confidence in the 0.9% AFR is much more reasonable.

3,000 Boot Drives

We always exclude boot drives from our reports as their function is very different from a data drive. While it may not seem obvious, having 3,000 boot drives is a bit of a milestone. It means we have 3,000 Backblaze Storage Pods in operation as of December 31st. All of these Storage Pods are organized into Backblaze Vaults of 20 Storage Pods each or 150 Backblaze Vaults.

Over the last year or so, we moved from using hard drives to SSDs as boot drives. We have a little over 1,200 SSDs acting as boot drives today. We are validating the SMART and failure data we are collecting on these SSD boot drives. We’ll keep you posted if we have anything worth publishing.

The Hard Drive Stats Data

The complete data set used to create the information used in this review is available on our Hard Drive Test Data page. You can download and use this data for free for your own purpose. All we ask are 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.

If you just want the summarized data used to create the tables and charts in this blog post you can download the ZIP file containing the CSV files for each chart.

Good luck and let us know if you find anything interesting.

The post Backblaze Hard Drive Stats for 2020 appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Post Syndicated from original https://www.backblaze.com/blog/backblaze-hard-drive-stats-q3-2020/

As of September 30, 2020, Backblaze had 153,727 spinning hard drives in our cloud storage ecosystem spread across four data centers. Of that number, there were 2,780 boot drives and 150,947 data drives. This review looks at the Q3 2020 and lifetime hard drive failure rates of the data drive models currently in operation in our data centers and provides a handful of insights and observations along the way. As always, we look forward to your comments.

Quarterly Hard Drive Failure Stats for Q3 2020

At the end of Q3 2020, Backblaze was using 150,974 hard drives to store customer data. For our evaluation we remove from consideration those drive models for which we did not have at least 60 drives (more on that later). This leaves us with 150,757 hard drives in our review. The table below covers what happened in Q3 2020.

Observations on the Q3 Stats

There are several models with zero drive failures in the quarter. That’s great, but when we dig in a little we get different stories for each of the drives.

• The 18TB Seagate model (ST18000NM000J) has 300 drive days and they’ve been in service for about 12 days. There were no out of the box failures which is a good start, but that’s all you can say.
• The 16TB Seagate model (ST16000NM001G) has 5,428 drive days which is low, but they’ve been around for nearly 10 months on average. Still, I wouldn’t try to draw any conclusions yet, but a quarter or two more like this and we might have something to say.
• The 4TB Toshiba model (MD04ABA400V) has only 9,108 drive days, but they have been putting up zeros for seven quarters straight. That has to count for something.
• The 14TB Seagate model (ST14000NM001G) has 21,120 drive days with 2,400 drives, but they have only been operational for less than one month. Next quarter will give us a better picture.
• The 4TB HGST (model: HMS5C4040ALE640) has 274,923 drive days with no failures this quarter. Everything else is awesome, but hold on before you run out and buy one. Why? You’re probably not going to get a new one and if you do, it will really be at least three years old, as HGST/WDC hasn’t made these drives in at least that long. If someone from HGST/WDC can confirm or deny that for us in the comments that would be great. There are stories dating back to 2016 where folks tried to order this drive and got a refurbished drive instead. If you want to give a refurbished drive a try, that’s fine, but that’s not what our numbers are based on.

The Q3 2020 annualized failure rate (AFR) of 0.89% is slightly higher than last quarter at 0.81%, but significantly lower than the 2.07% from a year ago. Even with the lower drive failure rates, our data center techs are not bored. In this quarter they added nearly 11,000 new drives totaling over 150PB of storage, all while operating under strict Covid-19 protocols. We’ll cover how they did that in a future post, but let’s just say they were busy.

The Island of Misfit Drives

There were 190 drives (150,947 minus 150,757) that were not included in the Q3 2020 Quarterly Chart above because we did not have at least 60 drives of a given model. Here’s a breakdown:

Nearly all of these drives were used as replacement drives. This happens when a given drive model is no longer available for purchase, but we have many in operation and we need a replacement. For example, we still have three WDC 6TB drives in use; they are installed in three different Storage Pods, along with 6TB drives from Seagate and HGST. Most of these drives were new when they were installed, but sometimes we reuse a drive that was removed from service, typically via a migration. Such drives are, of course, reformatted, wiped, and then must pass our qualification process to be reinstalled.

There are two “new” drives on our list. These are drives that are qualified for use in our data centers, but we haven’t deployed in quantity yet. In the case of the 10TB HGST drive, the availability and qualification of multiple 12TB models has reduced the likelihood that we would use more of this drive model. The 16TB Toshiba drive model is more likely to be deployed going forward as we get ready to deploy the next wave of big drives.

The Big Drives Are Here

When we first started collecting hard drive data back in 2013, a big drive was 4TB, with 5TB and 6TB drives just coming to market. Today, we’ll define big drives as 14TB, 16TB, and 18TB drives. The table below summarizes our current utilization of these drives.

The total of 19,878 represents 13.2% of our operational data drives. While most of these are the 14TB Toshiba drives, all of the above have been qualified for use in our data centers.

For all of the drive models besides the Toshiba 14TB drive, the number of drive days is still too small to conclude anything, although the Seagate 14TB model, the Toshiba 16TB model, and the Seagate 18TB model have experienced no failures to date.

We will continue to add these large drives over the coming quarters and track them along the way. As of Q3 2020, the lifetime AFR for this group of drives is 1.04%, which as we’ll see, is below the lifetime AFR for all of the drive models in operation.

Lifetime Hard Drive Failure Rates

The table below shows the lifetime AFR for the hard drive models we had in service as of September 30, 2020. All of the drive models listed were in operation during this timeframe.
The lifetime AFR as of Q3 2020 was 1.58%, the lowest since we started keeping track in 2013. That is down from 1.73% one year ago, and down from 1.64% last quarter.

We added back the average age column as “Avg Age.” This is in months and is the average age of the drives used to compute the data in the table and is based on the amount of time they have been in operation. One thing to remember is that our environment is very dynamic with drives being added, being migrated, and leaving on a regular basis and this could impact the average age. For example, we could retire a Storage Pod with mostly older drives and that could lower the average age of the remaining drives of that model while those remaining drives got older.

Looking at the average age, the 6TB Seagate drives are the oldest cohort, averaging nearly five and a half years of service each. These drives have actually gotten better over the last couple years and are aging well with a current lifetime AFR of 1.0%.

The Hard Drive Stats Data

The complete data set used to create the information used in this review is available on our Hard Drive Test Data webpage. You can download and use this data for free for your own purpose. All we ask are 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.

If you just want the summarized data used to create the tables and charts in this blog post, you can download the ZIP file containing the MS Excel spreadsheet.

Good luck and let us know if you find anything interesting.

The post Backblaze Hard Drive Stats Q3 2020 appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.