Backblaze Hard Drive Stats for 2018

I think it is over the time they have had the drive, not over the reporting interval. It's a measure of the age of the drives. Assuming their drives are operating 24/7, that means that those particular 50 drives have been in service an average of 461 days.

I'd expect on next year's report, those particular drives will show up as 49 drives with around 42000 drive days, assuming they aren't replaced by then.

> Comcast has 1TB/month data cap

I have three suggestions, but I have only tried the second suggestion, so please do your own research before my bad advice costs you a lot of money. :-)

1) Comcast (at least in many places) allows you to exceed your bandwidth cap for two months before clamping down on you. I think they are trying to prevent serious long term abuse, not a one time overage. So if you have 3 TBytes and can get it uploaded in one or two months, just do it, apologize, and it won't cost you anything. Backblaze only does "incrementals" after the initial upload.

2) Personally I have Comcast and I pay them an extra $30 or so per month for "unlimited" (remove the cap). Now when I look at my usage, my family stays just under the 1 TByte limit ANYWAY, so this is wasted money, but I don't want to stress about it, and I run like 5 Nestcams CONSTANTLY streaming video, plus my family loves Netflix, so I just drop the $30 and relax. So you could call up Comcast and change over to "unlimited" if you can afford it.

3) A modification of #2 that I have NOT TRIED is to raise it to "unlimited" for the duration of the initial backup. I don't know if you have to commit to a year of unlimited bandwidth, or six months, or if you can change at any time?

> Do you have as well "backups"? Or is that in the hands of the customers/users?

If you store data in Backblaze, there is no "backup" of that data. If Backblaze ever lost 4 drives simultaneously and could not recover the data, the customer would lose data. This is much like Amazon S3.

In general, we recommend a 3-2-1 backup strategy where there are 3 copies of the data, at least 2 copies on your site, and 1 copy in the cloud. You can read about that philosophy in our blog post here: https://www.backblaze.com/blog/the-3-2-1-backup-strategy/

If it was half failed we would DEFINITELY pull the drive out because it is already 1 drive down out of 20 for half the files. A lot of times the IT guys will make a judgement call that a drive is acting funny or slightly off so they just "fail it on purpose" which means yank it and replace with a new drive. We have done this just because a drive is "slow" (slow can mean the drive is having trouble writing data reliably on one attempt), or because some SMART stat looks wonky.

To provide more color, if a 20 drive "tome" (as we call it) is 1 drive down, we don't even wake people up in the middle of the night, but Backblaze datacenter employees replace it when they arrive at the datacenter the next day at 8am. All drives having problems are replaced by 5pm when the employees go home. This is completely business as usual, about 5 - 10 drives fail every day.

However, if 2 drives fail out of 20 (or 1.5 in our example above), pagers go off, people wake up and get out of bed at 3am and start driving towards the datacenter. Or we employ "remote hands" to swap the drives immediately, it depends on the capabilities of the night crew in the datacenter which varies by datacenter. "remote hands" is a contract service where semi-skilled technicians work for the datacenter and we can pay them $80/incident or there abouts to do things you can only do "in person" like replace drives. All the pods (where data is stored) have "base board management" which means as long as they are powered up and online we can log in remotely from home or office to figure out what is going on and fix a variety of problems. AUTOMATICALLY if 2 drive fail we stop sending any data into that "tome" of 20 drives. We have found that writing to drives causes more failures, so not writing to them is safer.

If 3 drives fail, it is instantly a "Red Alert" at Backblaze and a whole lot of official procedures kick in. An "incident manager" is assigned and the whole company's number one concern is to drop EVERYTHING and never sleep again until the Red Alert is lowered to Yellow. We light up a "situation room" (in Slack - our internal chat tool) and information and status is relayed through that.

SIDE NOTE: Backblaze has a relationship with an excellent company named "DriveSavers" who can recover SOME data off of failed drives. This is very expensive (thousands of dollars per drive) so we only do it to test the procedure and then in extreme situations. Three drives down is an extreme situation and extremely rare, so ALL OF THE THREE FAILED DRIVES would be immediately hand carried to DriveSavers even while we rebuild the customer data from parity. Notice Backblaze STILL has a complete copy of the customer data on 17 drives -> But if a 4th drive dies, the hope is we can recover at least one of the drives via DriveSavers thus saving the customer data. (We need at least 17 out of 20 drives in a "tome" to reconstruct the data.) In our experiments, DriveSavers seems to recover about half the drives, or in some situations half the data from a drive (imagine if 1 platter on a drive has a head crash and is destroyed, but the other platters are fine). We have made the decision that it is less expensive (for the same durability) to pay DriveSavers the thousands of dollars rarely instead of increasing parity to allow reconstructing data from 16 out of 20 drives instead of the current 17 out of 20 drives.

It would depend on the effort to do the methodology vs. the expected return (savings of finding a failed drive times the probability).