Windows Storage Pool Error: How do I repair?

I have a storage space on my personal computer that consists of 3 drives. My storage space is setup as parity. My pool has exhibited some shaky behavior recently in which the pool would go offline when ever I would do a large IO process such as a large file copy. Without really trying any other troubleshooting, a simple reboot would resolve the issue and my pool would be back online. About 2 nights ago I attempted to delete a very large folder full of files and my pool went down. I rebooted but this time my pool did not come back online. I have a fairly recent backup (I was actually in the middle of setting up a new backup to google when this happened, if you can believe that luck) but I'd still like to recover from this if at all possible. Below are a number of screencaptures which I have taken of the various things I have used for diagnosis.

Storage Spaces:


Disk Management:


PowerShell:


Hard Disk Sentinel:


All disks appear to be in good working order, the pool is merely offline and I can not get it to come back online. Aside from deleting the large directory of files, nothing has changed. I have not installed any Windows updates for several weeks. I've tried rebooting several times and I've also tried plugging in an additional drive as the Storage Spaces screen suggests. Any further insight/ideas would be appreciated!

Thanks,
Mike

Oh yes, I don't know that it is actually relevant but..... I was on here some months back with another somewhat similar Storage Pool issue which happily I was able to resolve.

How do I recover/repair my storage space?

Disk is offline if you are having same issue as the person of this youtube video please follow his instructions but only if the hard disk that is offline has a collision with another signature.


Fix Disk is offline because it has a collision with another signature error problem

FreeBooter said:

Disk is offline if you are having same issue as the person of this youtube video please follow his instructions but only if the hard disk that is offline has a collision with another signature.
Fix Disk is offline because it has a collision with another signature error problem

The disk is offline due to "critical write failures" so unfortunately this didn't work for me.

Looks like seagate HDD if its use there diagnostic tool instructions are below. If its WD HDD use there Data LifeGuard Diagnostics to perform EXTENDED TEST - performs a Full Media Scan to detect bad sectors. Test may take several hours to complete depending on the size of the drive.


Please download and run SeaTools for Windows.

Before the installation begins you will be prompted to either Decline or Accept the terms of the installation, click on I Accept.



1. Once the installation begins SeaTools for Windows will search for HDDs and SSDs on your computer.

2. Detected Drives will list the HDDs and SSDs found. Place a check mark in the drive box you want to run the scan on. This should be the drive that has the operating system installed on it, this is usually C: drive.

3. You will see Basic Tests toolbar above Detected Drives, move the mouse pointer over this to open the test options. Please click on Long Generic Test

4. This will start the scan. When the scan is complete you will see the result under Test Status , please post the results in your topic.

5. The test will indicate either Pass or Fail. Post the results of the scan in your topic.

6. Click on Help, then click on View Log File. If the scan failed take a screen shot of the Log File and post it in your topic.

I installed both Data LifeGuard and SeaTools and ran tests on all drives. Everything appears to be passing.

Try to bring the disk online instructions are below.

How to Offline/Online a disk using Diskpart

FreeBooter said:

Try to bring the disk online instructions are below.

How to Offline/Online a disk using Diskpart

Ok so, that worked! Unfortunately the fix was temporary as a rebooted my machine and when it came back up the disk was offline again. I can use diskpart to bring it back but not a permanent fix.

The disk also appears to be in readonly mode.

FreeBooter said:

After you have bring the HDD online execute below commands for that HDD.

Code:

attributes disk clear readonly

Exit

Chkdsk  X:  /r

Replace X: drive letter with the drive letter of the HDD you want to repair file system and bad sectors.

Running the "attributes disk clear readonly in diskpart hung my machine for a good long while and eventually "completed" whereby what it actually did was knock my pool offline again.