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Lombardo_Ciccone

macrumors newbie
Original poster
Apr 15, 2024
6
0
Good day!

I am trying to mirror via RAID 1, two or more HDDs with one HDD. Is it possible? I would imagine partitioning would do the trick, but I don't see a way to do this when setting up RAID 1 in Disk Utility.
Am wrong, or am I missing a step?

Thanks for advice, folks.
 

chabig

macrumors G4
Sep 6, 2002
11,268
8,970
Sorry, I didn't understand your first post. After you create the RAID, it should appear to the system as a normal drive. You ought to be able to partition it like normal.

Though you didn't say, are you going to format it using APFS? If so, separate the data using volumes, not partitions. Volumes keep data logically separated but they share the space.

That said, be sure to backup this data. RAID 1 can help save from an individual disk failure, but there are other ways to lose data.


 

Lombardo_Ciccone

macrumors newbie
Original poster
Apr 15, 2024
6
0
Sorry, I didn't understand your first post. After you create the RAID, it should appear to the system as a normal drive. You ought to be able to partition it like normal.

Though you didn't say, are you going to format it using APFS? If so, separate the data using volumes, not partitions. Volumes keep data logically separated but they share the space.

That said, be sure to backup this data. RAID 1 can help save from an individual disk failure, but there are other ways to lose data.


Hi there.
Ah, Ok so I can partition it, but how do I specify which Volume (so yes, APFS file system) points to (mirrors) each HDD? That's what I have to do. Your help is being appreciated as we speak, since the link shows me how to set up the RAID 1.
I am manually (copy, paste) onto a spare HDD now, before setting up RAID 1.

However, the two links you provide are giving me food for thought.
Maybe I need to purchase Super Duper.
 

chabig

macrumors G4
Sep 6, 2002
11,268
8,970
how do I specify which Volume (so yes, APFS file system) points to (mirrors) each HDD?
I'm not sure what you are trying to do. You'll need two blank hard drives to set up the RAID. Then you can create as many volumes as you wish on that RAID. Is it your plan to create two volumes, and copy one existing hard drive to each volume? (I'm not even sure I put that question into words very clearly)
 

Lombardo_Ciccone

macrumors newbie
Original poster
Apr 15, 2024
6
0
I'm not sure what you are trying to do. You'll need two blank hard drives to set up the RAID. Then you can create as many volumes as you wish on that RAID. Is it your plan to create two volumes, and copy one existing hard drive to each volume? (I'm not even sure I put that question into words very clearly)
Hi there.

I have 2 external HDDs on a dock, and a RAID 1 HDD on another duck. All connected by USB 3.0 on iMac. (APFS for all HDDS).
I want the RAID 1 to mirror whatever work, or addition of files, that occurs on the first 2 external HDDS.
So, does this mean, I need to create operate volumes for each of the first 2 HDDs?
That's what I need to do.
 

HDFan

Contributor
Jun 30, 2007
6,628
2,865
I am trying to mirror via RAID 1, two or more HDDs with one HDD.

If this is for backups what is your plan for the other 2 in the recommended 3-2-1 backup strategy?

Once setup there are a number of programs which can do the synchronizing: Chronosync, Carbon Copy Cloner (on demand only), ...
 

Lombardo_Ciccone

macrumors newbie
Original poster
Apr 15, 2024
6
0
If this is for backups what is your plan for the other 2 in the recommended 3-2-1 backup strategy?

Once setup there are a number of programs which can do the synchronizing: Chronosync, Carbon Copy Cloner (on demand only), ...
I've heard of Chronosync, bought CCC 10 years ago, but I have to pay for a new version since my old serial won't work. RAID 1 is free, so I need to try that. Ill look into Chronosync.
I have Time Machine as. backup, and I am subscibed to Carbonite. So 2 local backups (Time Machine and RAID 1) and 1 offsite backup in the cloud.
 

NC12

macrumors regular
Nov 12, 2020
108
261
Ah, Ok so I can partition it, but how do I specify which Volume (so yes, APFS file system) points to (mirrors) each HDD? That's what I have to do. Your help is being appreciated as we speak, since the link shows me how to set up the RAID 1.
I am manually (copy, paste) onto a spare HDD now, before setting up RAID 1.
I don’t think that is what you should be doing. I don’t think that is even possible. Why not get another drive and make 2 raid 1 setups
 

Lombardo_Ciccone

macrumors newbie
Original poster
Apr 15, 2024
6
0
I don’t think that is what you should be doing. I don’t think that is even possible. Why not get another drive and make 2 raid 1 setups
I see. Maybe I should just splurge on a new HDD. I'm trying to save money. But I'f I cannot have the RAID 1 drive mirror 2 HDDs, then I have to abandon this plan.
 

leifp

macrumors 6502
Feb 8, 2008
342
318
Canada
You need a RAID enclosure to have RAID drives. Some use hardware, some use software, but there’s a distinct difference between mirrored drives and duplicating drives. I’m confused as to
1. What your actual setup is (no such thing as a single drive RAID, it’s a single array)
2. What you want to do… backup a disk? Have an array that has redundancies to allow for failure tolerance? Something else?

Personally I have a NAS in RAID 5, which is a networked 4 disk array. I back up my computers on that (GOOD) but I also use it as a streaming server without further backup (NOT GOOD)…
 
Last edited:

Timpetus

macrumors 6502
Jun 13, 2014
283
564
Orange County, CA
I think it'd be best to abandon this plan, as it isn't really the best way to set up a RAID. It might be possible, but you'll be losing a lot of the benefits by bottlenecking the I/O with 1 drive shared among the two separate RAIDs. It's typically considered best practice to purchase multiple drives of the same type and capacity and RAID them together from the start. I've done some odd things like shucking older HDs and popping them in an enclosure together as a RAID 1 setup but that's just for data I don't care about too much. I don't trust my more important data to anything less than my RAID 5 with backups.
 
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