Preferred Digital Music File Backup?

I am trying to decide how to best protect the files that took many hours to rip.
How do you backup your files? Cloud or Hardrive? If Cloud...which service do you use?
Thanks in advance.
Good question.  I back up to my own drive but have considered the cloud. 
While I understand that some cloud services will mail a drive containing your files to you if it ever becomes necessary to restore them, keep in mind that downloading a large backup from the cloud may take an absurdly long time.

For example, if you have say a 100 mbps Internet connection, which is fairly fast, and if the download speed is not limited by the speed of the service at the other end, or by any of the servers in between your computer and their server (all of which are optimistic assumptions), downloading 2 Terabytes will take more than two days of non-stop downloading. While a reasonably fast external mechanical (non-SSD) hard drive connected via USB 3.0 (or higher) should be able to do that in around three hours or less.

Also, since upload speeds are usually a lot slower than download speeds, if a 2 TB music collection were to be uploaded all at once it would take far longer than those two days. Probably more like a week.

I would therefore recommend backing up to at least one (and preferably two) external hard drives that are in your possession, at least if you have a large amount of music to back up.

-- Al

Yes @almarg you are right about the restore time.  Sending a physical device to restore is needed. Who does that?
My digital files reside on a NAS.  I have about 3 TB of files.  I recently started using Robocopy, a program that is included with Windows, to create a mirror copy of my files to an external HDD.  I learned how to use Robocopy by watching a YouTube video.  I can store the drive in my safety deposit box.
Sending a physical device to restore is needed. Who does that?
That is a service offered by iDrive. The company will also send you a drive to load your files onto, saving you the burden of dealing with slow uploads.

I back up to external HD and iDrive and have been happy with their service.
I back up to a solid state drive on my computer which is only for music back up.  I also have a USB hard drive I back up the music files on.  I have 2 different back ups.  I did this because I lost all my files once with no back up and spent the next year re-ripping all my cd's.
A little off-subject, and totally optimistic, but I feel our tech overlords should offer lifetime streaming of any album on CD we have purchased.
We would send the CD to "them" and have permanent streaming rights.

"They" want to discontinue physical media forever and this would encourage people enter the streaming world. Once you are "on board" with streaming, any new purchases would be virtual. I have yet to stream as it seems to me like a gooey mess that I can't understand and have no reason to try. C'mon fat cats, give me a reason to switch.

GooglePlay music does exactly what you describe but unfortunately compressed for now.
Data backup on Cloud can get damaged many ways.  It can be deleted/overwritten by user's mistake or malicious attack on his or Cloud computer (or major Cloud hardware/software failure).  To me internet storage is only acceptable as a second backup, that should be outside of the home anyway (fire, theft etc.).  I keep music on HD drive and two HD backups (one outside of home) - total of 3 drives because it is possible that, while updating backup, something (like virus, controller failure, my mistake etc.) will damage both drives.
I update only one backup (stagger them) at the time and only after 5-10 new CDs added.  It is very safe, since unpowered, disconnected drives in storage tend not to fail.
Good cloud storage includes versioning so human error is avoided and good ones are encrypted limiting hacks. Virtually all quality cloud storage has multi site redundancy.
Those top-6 never resulting in more than a few hours of data loss in one case. The Tencent was an anomaly.

Compare that to the horror stories many have w.r.t. backup failures that they thought were "robust".  Real time mirroring of your data, secure multi-location storage with robust protocols, background operation requiring no additional work except making sure the connection is live is going to be on average much safer.
I use Google drive since it is cheap and I don't have much music. If I would have more I would try Backblaze. And of course a local copy on a USB-disk.

I would not only use a local disk.
With the quality, convenience and cost of streaming these days, honestly, I can be bothered with physical media any more.
Music, photos, and other data is stored on a NAS Raid 1, I have two portable hard drives that I back this up to, one resides at home and the other locked up at work.