Does macOS support hardware RAID or software RAID

First, I would never do any RAID setup with individual USB or Thunderbolt drives as part of the array. It is much too fragile and prone to failure since you have two cables/connections to worry about. If either cable disconnects for any reason (or either drive for that matter), then your RAID will be in a degraded state requiring a rebuild. You definitely want to use a multi-drive enclosure.

I personally avoid most hardware RAID setups because you are locked into that provider's ecosystem in case the enclosure fails since you need another one of their enclosures to be able to access the data on those drives, otherwise you are in for a lot of work. Using software RAID allows you to move those drives to any other enclosure if the original enclosure fails. A hardware RAID usually has better performance since the RAID enclosure is doing all the work to maintain the RAID array, while a software RAID is all done by the computer itself. A NAS as suggested by @BobHarris may utilize hardware or software RAID, but the NAS device is controlling the RAID since it is an independent device on the network & not physically connected to your computer.

Depending on how you intend to use the RAID will determine if you should go with a RAID enclosure that directly connects to your computer, or a NAS which is only accessed across your network (usually just your local home network).

I am really concerned about how you wish to use a RAID storage solution. A RAID in & of itself is not a backup. A RAID is meant to allow the data stored on the RAID device to be online in case of a drive failure....hopefully being able to rebuild the array before another drive fails & you lose the data. If you make a catastrophic edit or deletion for something stored on the RAID, then that becomes your only copy unless you have another copy of the file before the catastrophic edit/deletion. Now a RAID device can be a backup destination since it will hold a second copy of the data where the original copy of the data is on your computer or on some other external media.

A good backup is 3-2-1

3 copies of your data, and mirrors do not count. But the original is the 1st copy

2 backups, to separate external storage, and preferably using to different backup software programs. Avoids a single point of failure. If you want to use separate RAID devices for each storage system, that is fine.

1 copy off-site, which could be a network backup, or you take your laptop to work and make a backup every work day, or you carry a backup disk to an off-site location on a regular basis. This avoided disasters and theft. This is also the hardest one for most people to deal with, either because of the trouble in doing it, or the network storage expense.

If there are more backups, even better, but 3-2-1 is a solid backup strategy.

If you multiple layers of backup, then I would setup Time Machine and give it multiple drives. It will provide an incremental backup each hour, rotating through the provided drives, so each backup drive is no more than 2 hours out-of-date, if you use 2 drives, or 3 hours out of date if you use 3 drives, etc...

If you want RAID, I would get a NAS (Network Attached Storage) such as Synology, or similar, and allow that device to worry about the RAID. You can setup up mirroring, or RAID 5 (multiple disks with the ability to loose 1 drive), you can setup RAID 6 (with multiple disks and the ability to loose 2 drives). You can specify a "Hot Spare" so that if you do loose a drive, the hot spare will be swapped in and the data properly spread across the hot spare. You can then replace the bad drive and make it the new hot spare.

You can also get USB based external hardware RAID boxes.

But if you really want macOS software RAID support

Create a disk set using Disk Utility on Mac - Apple Support

macnerd48 wrote:

I considered NAS but I'd have to spend hundreds of dollars just for the enclosure plus hundreds more for the drive. Then I'd have to find a place to put it & plug it in. I agree with the above comment about buying the portable USB RAID or the Synology enclosure. If it should fail or I drop it, I'm out of luck.

You do not generally carry around a Synology or other external RAID device. Well maybe one of the smaller 2 drive RAID devices, but generally dropping is not an issue. Location can be anywhere. I have one in the basement next to the comm gear, and a 2nd one in another part of the house above the basement that backs up the first (I do have my home wired for Ethernet, including in closets with power outlets, so it was not a problem for me; I understand if your situation is not as easy).

That's why I'm intrigued about software RAID. Does macOS computer have a hardware RAID chip on the motherboard or is macOS software RAID?

No hardware RAID chip. Apple only has a Software RAID via Disk Utility as described in previous replies.

I think that Disk Utility allows one to add a hot spare.

The "man diskutil" man page does indicate support for a Hot Spare.

Does Time Machine only back up the entire hard drive (SSD) or can I use Time Machine to back up a specific folder & use Time Machine like Google Drive?

Time Machine does the entire drive BUT it does allow you to EXCLUDE directories. But building a list of directories to exclude just so you can backup a specific folder would be a pain.

Carbon Copy Cloner would be better for backing up selected folder trees.

I would just use a different backup utility for each drive (which I actually do), and then I have redundant backups, and I have avoided single point of failure. If you are not interested in multiple backup utilities, then Time Machine with 2 drives and allow Time Machine to alternate each hour's incremental backup between each drive.

I would not focus on RAID, unless you are going to mass storage. But just to Mirror 2 drives, is not the best use of your external drives.

Mirrored drives are more for must have reliable server storage for a business that cannot afford to stop offering its services. They would RAID (maybe even triple mirror), but also have backups separate from RAID, or even have a real-time replication operation going to a separate system so if the data center dropped off line, the remote system could take over with minimum loss of service.

That is where Mirroring is useful. Your suggested usage is less so.

macnerd48 wrote:

HMM, more research is necessary!

I'm sorry that I'm asking so many questions! I'm almost done, fingers crossed!

This is how we learn. Some topics such as this one are a bit more complicated to explain & understand.

I'm guessing that a NAS would have 1 Ethernet cable coming out of the box & going into the computer. I'm living at my parents' house. The router is maybe 30 feet away in another room. I had to get an extender because of the weak signal. Can the NAS be wirelessly connected to the router or must it be physically connected to the router by Ethernet?

It depends on the NAS. A wired Ethernet connection is usually faster, more stable & reliable than WiFi especially if you have a weak signal. Physical items between the device & the wireless access point will impact the WiFi signal as will some appliances & running machinery that can cause noise which interferes with the WiFi signal.

If you have a good WiFi connection and connect using a high bandwidth wireless channel & protocol, then you can get decent speeds depending on how the NAS is used (types of content & number of connections to it from other devices).

External USB-based hardware RAID boxes are what I'm interested in. How many USB cables do I need for an external USB-based RAID enclosure?

For a multi-drive USB enclosure, it should just be a single USB3/4 or Thunderbolt3/4 cable depending on the ports & protocols supported by the enclosure.

I watched a YouTube video where the narrator had an portable external USB-based RAID enclosure with 2 NVMe sticks. There were 2 USB cables coming out of the enclosure.

No idea what they are using or doing. It is possible there are such multi-drive enclosures out there, but I would not want such a setup.

Let's say that I want to have a portable external USB enclosure with 3 disk RAID mirror. In the video, there were 2 USB cables. Would a 3-disk portable enclosure have 3 cables - 1 for the original disk, 1 for the copy disk & 1 for the spare?

First if you were using three disks, you would have two of them in a RAID 1 mirror and the third would be marked as a hot spare so if one of the two active drives failed, the RAID would automatically try rebuilding the array using the third disk marked as a hot spare.

FYI, you have to be careful with the stuff you find online. There is a lot of junk & misinformation out there. Plus there are a lot of things online where technically it will work, but it is in no way a good idea. A lot of people post stuff just to get views & followers, or to show off.

You also have to be very careful these days when buying hardware. Again, there is so much junk hardware out there....sometimes even from respected brands & vendors. There are many "no name" new brands (mostly from China) which are selling cheap (in both senses of the word) devices ... they are basically trying to steal business from the legitimate manufacturers & vendors who have traditionally provided good quality products by preying on people who don't want to pay for anything these days. Many of those "no name" brands sell products that tend to be unreliable, but many times can be unsafe (potentially dangerous to your expensive computer and/or physically dangerous to your and/or your home due to electrical or fire hazards). Of course once in a while those cheap knock-offs will sometimes be better than some of the expensive items sold be respected brands/vendors....there are always exceptions to every rule.

Since it is not your home, and I assume you are just getting started in life, I would keep it simple, and any money saved I would put into your Roth 401K and/or Roth IRA.

Simple would be 1, not very expensive, external disk and Time Machine.

At most 2 external drives, and let Time Machine rotate between the 2.

If you are working in the computer industry, then maybe invest in extra hardware to experiment with as a way to learn, but do not spend all your money on this, as you need to save some for the future.

The experiments can be on small, even less expensive external drives, where you do not care if the data is lost, because you are using it as a learning tool.

Retired. Now you are speaking the language of most of the frequent contributors 😁

So now you are spending your 401k and IRA money.

If you want the storage to archive stuff so that you do not loose it, and you do not want to put it on your Mac's internal hard disk, they multiple external storage devices. And Google drive can be one if you like.

Your 300 CDs are going to take up at most 200 gigabytes of storage (most likely less as albums do not always use all the space of a CD).

If you do not want the Ripped CD's on your Mac's internal disk, then an archive disk that has its own backup. Time Machine can include multiple disks to be backed up. In fact unless you explicitly exclude external physical disks, Time Machine try to back them up.

If you are going with an external archive storage for your CDs and anything else you want to save, then figure out the size you need. Given the current storage market, then a 1 or 2 TB external drive, either rotating disk (less than $100) or SSD/NVMe storage($100 - $200) is not too expensive.

Once you know how much storage you need to backup (your Mac's storage and your archive storage), then buy 1 or more external disks that are at least twice as large as all the storage you need to backup so that Time Machine has extra room to keep several generations of incremental backups, before it has to start purging older stuff.

As mentioned before, Time Machine can have 1, 2, or more target storage devices it it backing up to. It will just rotate around the target disks each hour when doing its incremental. So you have backup in depth.

Under no circumstances should you consider a backup utility as an archive, even if the utility keeps older versions of files, because eventually the backup utility will purge files that are no longer on the source disk(s). If you need an archive, you have a dedicated disk(s) for the archive, and you make sure they get backed up as well.

Now if you want to talk about using a NAS instead of direct attached disks, then that can be put next to the ISP router/WiFi device, and you would access it over your home network. So a NAS does not need to be next to your Mac.

And since you mentioned weak signals. Getting a WiFi Mesh network might give you better WiFi performance, instead of a repeater. Although if the repeater is positioned so it gets a strong signal and then provides you with a strong signal, that would be good.

Oops. Wife just called me for dinner.

Great advice there from @BobHarris.