Help! disk is suddenly read only

Version 5.5.5 of SoftRAID will help prevent this issue.

Yes, Disk Warrior is a way to fix it. When Disk Utility cannot repair minor volume damage, it will either mount the volume "read only", or not allow the volume to mount at all. Disk Warrior is the only third party product that can repair such problems reliably.

Otherwise, a backup/erase with SoftRAID/restore is an option.

These events should be rare, but since OS X (and Apple hardware) has this bug where disks can drop out unexpectedly, that can cause volume issues and the problem you are having.

We hope the new APFS file system prevents all these issues from happening, but that is 2018.

so techtool is ok to use to try to fix this?

I don't think it is capable of repairing this. From my knowledge, it essentially uses a variation of fsck.

Disk Warrior can genuinely replace a directory with a new one built from scratch.

I should try disk warrior I guess.

I have a new 32 tb thunderbay 4 with this same issue two weeks after purchase.
I hate to buy the disk warrior software as a solution to this problem.
This is a lot of money to spend to have these issues already.
I do of course have another raid drive setup with a daily backup of the thunder bay 4 drive. Hope they get this issue worked out.
Erase and backup is a timely operation.
Hope this is not something that happens regularly.
New imac pro, High Sierra and latest softraid xt 5.6.7
Also the Thunderbay came with a longer 60 inch active cable and the fastest write speed I have seen is around 100mbps.
I will follow this thread to see if any other solutions are found.

On the performance issue, check to see if your SoftRAID app is quarantined:
that is what I would expect.

Run the terminal.app. You need to do two things:
Run the xattr command
enter the path to the application you are checking. Fortunately, terminal supports "drag and drop", so this is not difficult to do.

Enter this command: (with a space at the end)
sudo xattr
Now, find SoftRAID application and "drop" it into the terminal window. This will put the path to the app.
Hit "enter".
The terminal will either return nothing, or Say it is quarantined.

If it is quarantined, you need to remove SoftRAID from quarantine, then restart.

Here is the command that will fix this:

sudo xattr -r -d com.apple.quarantine

(You need to enter the path to SoftRAID again, as before. Type a space, then drop SoftRAID into the terminal window to get the path)

then run the first xattr command again, to confirm that this is clear, there should be no output.

Now restart. Performance should be much better.

Second, regarding the volume needing repair. We believe this is an OSX bug triggered by one of two things:
Disks "ejecting" from the bus
OS X Updates that shut down SSD startup drives before the HDD's can save cached data, and cause minor directory damage, that ultimately results in the above issue.

when 10.14 is released, SoftRAID should be in a position to support HDD's with APFS file system and retain good performance. This should eliminate directory issues. (We hope!)