The Cost of Homelab Backups
If you ave a homelab, you’ve probably collected a few TB of data that needs backed up. Recently in /r/datahoarder and /r/homelab I’ve seen a lot of posts that ask about backups. I’ve talked about my strategy in the past , but I figured I dive a bit more into offsite backups.
If you’re not familiar with why you should be keeping backups or some general rules of thumb, I have some information over here. Basically, you should always keep backups of your data and those backups should include offsite copies in case the worst happens to wherever your lab lives.
I’m not going to get into the specifics of backups, but know that you need to take backups!
Offsite Backup Providers
There are a lot of options for keeping your data somewhere else, but the big idea here is to be geographically separate. Depending on your level of paranoia, this can be something like a few miles away, a thousand miles away, or a few continents away.
Here are the options we’ll compare:
AWS S3
The big-name provider choice, this is AWS’s data storage service that can store any amount of data at a fixed rate. It has multiple access tiers that determine your cost but also how long it takes to read data. Some tiers have instant data access, but Glacier tiers require you to request a data read and then AWS will make it available in a few hours.
Backblaze B2
Backblaze is a company that’s been doing cheap data storage for a long time, and offers a object storage service like S3 called B2. It has the same interface as S3 but has only one tier.
Buddy’s House
If you have friends or family that live nearby, you can put a NAS or external hard drive there and back up to it. If they also need backup space, you can probably arrange a mutual swap where you put a NAS at their house and they put one at yours. Depending on how nice your friends are, you can do this for free but are on the hook for hardware and troubleshooting, especially if the friend isn’t tech-savvy.
Colocation
Same idea as the friend’s house, but your friend happens to own a data center and is much more focused on money. Lots of data centers can rent you 1 or 2 U of space for a reasonable price where you can stash a NAS and backup to it. Again, you’re on the hook for hardware and driving over there to install and maintain it.
Costs
For any backup, we need to consider a few aspects that may contribute to the cost. If you just store data things are simple, but in my case I do a few test restores per year and check a random subset of data each month, so we need to consider more factors. These are the major costs I consider in this post:
- Monthly Storage Fees - This is the simple Cost per GB the provider charges to store your data.
- Data Transfer In and Out - The costs to upload (usually free) or download (usually not free) data back out of the cloud.
- Appliance Fees - If you need a lot of data fast, some providers can ship you a device with your data on it. Some providers do this for free, others charge.
I’ll break down costs for common events for each of the providers we’re comparing in each section.
Data Storage and Checks
This is the most basic thing an offsite backup does. For this section, I’m looking at the cost to store 5 TB of data and read back 10% of it (500GB) as a check each month.
AWS is an easy first choice, with S3. If you go for the Standard storage tier, they’ll charge $0.023 per GB. If you go with Glacier Deep Archive, that drops to $0.00099 per GB. If your backup program cant tolerate the delayed reads, you can look at something like One Zone Infrequent Access, which runs $0.01 per GB.
As we read the data out to check it, we’ll be billed for outbound bandwidth, which is $0.09 per GB for AWS if you’re leaving AWS. If you’re using Glacier, you’ll also have to request the data to be restored to a readable state, which is $0.02 per GB.
Backblaze B2 has one rate of storage, $0.005 per GB, so it’s pricing is simpler but more expensive on the surface. Data transfer is $0.01 per GB.
The Colocation and and Buddy System vary in cost and bandwidth charges, as your colocation provider may impose data limits or your buddy’s internet connection may have data caps they can’t exceed without cost.
If we look at just storage, here’s where we stand. This assumes storing 5 TB and reading back 500 GB as a check each month.
| AWS (Standard) | AWS (Glacier) | Backblaze | Buddy / Colocation | |
|---|---|---|---|---|
| Storage Cost / mo | $115 | $4.95 | $25 | $0 + hardware |
| Data Transfer / mo | $45 | $45 | $5 | $0 |
| Data Restore / mo | $0 | $10 | $0 | $0 |
| Total Monthly | $160 | $59.95 | $30 | $0 |
As you can see, while AWS seems cheaper at first, adding in our restore costs quickly puts it over the edge. Also, while the Buddy system is $0, keep in mind the initial hardware required + the maintenance that now falls on you.
Full Restore (Downloading It)
If you need to do a full data restore, the simple way is to download the entire data set back out. We’ll be billed for bandwidth as we are with our checks, so things can get expensive quick. Again, we’re looking at our 5TB data set.
| AWS (Standard) | AWS (Glacier) | Backblaze | Buddy / Colocation | |
|---|---|---|---|---|
| Bandwidth | $450 | $450 | $50 | $0* |
| Restore | $0 | $100 | $0 | $0 |
| Total Cost | $450 | $550 | $50 | $0 |
When transferring large amounts of data from your buddy’s house, you might run into data caps set by the ISP, so the cost may be variable here. For the cloud solution, Backblaze is the winner here too.
Full Restore (Mailing It)
Another option for a full restore is to have the provider send you the data via a hard drive and a parcel service. AWS and Backblaze can do this for you, they write your data to a rugged hard drive and mail it to you with 2 day shipping.
For AWS, they charge a fee for the device rental ($60 for their smallest) + data transfer out per GB ($0.03).
Backblaze has a similar way, and they charge you a deposit on the hard drive of a $189 deposit that is refundable if you return the drive. They limit you to 5 drive refunds per year though, and each drive can hold 8TB.
For the buddy system, you can do the same thing by going and picking up the drive. Colocation you can do this too, but you may be limited to buisness hours to access things.
| AWS (Standard) | AWS (Glacier) | Backblaze | Buddy / Colocation | |
|---|---|---|---|---|
| Appliance Cost | $60 | $60 | $0* | $0 |
| Transfer Out | $150 | $150 | $0 | $0 |
| Total Cost | $210 | $210 | $0 | $0 |
While it seems silly, when moving more than a few TB of data, this is by far the fastest way, especially for limited home connections.
Overall Thoughts
B2 is the winner in this comparison. Backup restores and checks are important, and while the cost per GB of storage is more, you easily recoup that difference with the fees AWS adds for restores.
If you have a friend or way to keep a NAS offsite, that’s even cheaper per month, though keep in mind that you’re now on the hook to maintain this device.