AppleRAID-1 & SoftRAID 5.8.4
I've got a cMP 2010 w/ 2 x 4TB & 2 x 6TB HDs in the trays. Booting is from a Samsung SSD on a PCIe Card
Now, the two 6TB HDs are presently in AppleRAID-1. When I installed SoftRAID 5.8.4, the read/write speed to this AppleRAID fell to about 10 % of what it was beforehand. Removing the SoftRAID driver resolved the issue. Not using AppleRAID-1 isn't an option for me, as I need several of the features in APFS.
My idea was installing the two 4TB HDs in the DVD bays, buying 2 x 6TB HDs more, and formatting the resulting 4 x 6TB HDs in SoftRAID-5; but with this issue rearing it's ugly head, I've decided to go with OpenZFS instead. (& - yes - I've bought a license for SoftRAID)
Conclusion : SoftRAID is incompatible w/ AppleRAID-1.
Its not conceivable how this can be, as all the two respective drivers to is tell the OS who owns a disk. I have never seen this before and we test with Apple RAID and SoftRAID volumes frequently.
Its possible there is a SMART issue, we can test that. Go to SoftRAID preferences and disable SMART checks. Just to see if it makes a difference.
I am guessing ZFS is really slow on that machine. Give some feedback on performance if you don't mind.
You are running Mojave on this machine?
@softraid-support I've un-installed the SoftRAID driver & gone full OpenZFS RAIDZ-1 on 4 x 6TB HDs, so at present I don't have the capability to test, as I don't have any surplus HDs I can test on.
Another reason for me going OpenZFS is the advanced capabilities such as datasets & encryption on a per dataset - it's almost like APFS
As to OpenZFS being slow, I don't have any issues as far as I can see :
My workload is primarily VMs (Linux & Windows Server testing) & I've succeeded in getting to 256 GB RAM : 32 GB RAM modules in cMP
Except from SoftRAID, I'm a very satisfied OWC customer & I do plan to continue shopping with you.