But knowing SoftRAID quite well after everything that just happened, with the understanding that RAID is not a backup to begin with, is there any compelling reason why I should not just split off the secondary disk of each volume a non-RAID volume, delete the 4 disks volumes on the primary, then create a new single volume on said primary, transfer the data onto this new primary containing a single volume, and then convert that volume into a new mirror at the end?

Of course I'd confirm full backups prior to this. It wasn't really clear to me how backing everything up to a single new disk and then wiping the mirror would be any more secure than splitting the mirror using the pair already here. Isn't the vulnerability of a single-disk the same either way? 

But I believe that all those volumes are already on other disks in-house (making the mirror already a backup) and I'll check the offsite disks to find out about those too before doing anything at all.

Are the read operations against a RAID1 mirrored volume performed in a striped manner to increase read throughput?  Or are the reads operations performed only form the primary disk (with the secondary laying dormant / discarded / spare)?

I see the "I/O request" counter increasing on both primary & secondary, but it's not clear to me whether RAID1 offers a read speed benefit.

I ask because I'm evaluating whether a 3x disk RAID5 volume would generate better read performance vs. a 2x disk RAID1 mirror -- or whether they should produce -- effectively -- the same read speed.  Note: I'm putting aside differences in write performance (I understand that difference between RAID1 & 5).

Thanks!

a RAID1 connection of two disks "broke" recently ("secondary disk missing") - is there a way to re-connect these two disks gain, other then delete one of them and re-connect it?

SoftRAID 5.8.4 with matching drivers / macOS 10.13.6 - yep - old but gold

Best - Steffen

Am I doing something wrong or missing some step?

PS. I'm not super computer literate, but I do know enough to get in trouble and not enough to figure out how to make it better. 

Replace each disk in turn with a larger drive

Resize to the new disk capacity

I am very new to SoftRAID and RAID in general and I have a question about configuring RAID 1 for system disk that have your operating system on it to another disk.

It is a possibility to do it with this software? and if so, is there a step-by-step instructions on how to configure RAID 1 for the system disk using SoftRAID?

Thanks in advance for your help.

I looked around the SoftRAID site for RAID 1 performance information and struck out. 

Does SoftRAID's RAID 1 double read speeds?

(If so, this detail should be conspicuous.)

I have seen other threads mentioning "certifying" drives before creating volumes, but I can't really find much in the way of documentation about what that means or the details of that process. And since all of my enclosure bays are full, I'm not clear on how I would "certify" a new drive without breaking my existing volume(s). 

Any clarity or suggestions would be appreciated!

I can add the secondary disk to the APFS volume, which completes successfully according to the SoftRAID log, but the volume still appears as missing a secondary volume (I cleared the secondary disks before doing this), and the secondary disk shows too much available space. The primary disk has 134 MB available, while the secondary still has 3 TB.

As this is only for Time Machine I don't care that much, but would prefer to avoid wiping the volume.