ReadyNAS Pro Pioneer -- thought I was out of the woods -- dual disk dead recovery -- shares gone

ReadyNAS Pro Business Edition (X-RAID2), RAIDiator 4.2.31

Bought the pro pioneer empty and filled it with 1.5 Gb Barracudas a long time ago. Was getting lots of SMART error on disks 1 and 3 a few years back and replaced discs 1, 2, & 3 with WD30EFRX-68EUZN0 3 Gb 34,000 hours ago to replace the failing discs and up my storage volume.  In the last 6 mos disc 6 has been throwing more and more SMART errors, none from 5, and out of the blue, NAS let me know disc 5 was dead.  I did a hot swap with a spare 2 Gb Barracuda I had and it restriped and all was copasetic.

The SMART errors continued to increasd so I decided to replace disks 4-6 and up my storage again.  I ordered 3 WD40EFRX-68N32N0 disks and hot swapped disk 6.  The NAS immediately showed disk 4 as dead and volumes unprotected.   I shut down the NAS, removed the new disk 6 and replaced it with the old disk 6 and was informed that both disk 4 and disk 6 were dead and volumes unprotected ( I think that is the wording ).  So, I shut down the NAS and poured over this forum.  Used the advice from others, took out disk 4 ( since 6 seemed the sickest with all the SMART errors ) and cloned it to one of the new WD 4 gb using Acronis True Image.  Clone completed successfully, put disk 4 back in, restarted NAS, and it showed 4 was healty and only 6 was dead. I hot swapped 6 with one of the new WD 4 Gb, it tested fine and successfully restriped.  All seemed good, shares were accessible, so I went ahead and hot swapped disk 5 with the third of the new drives, it tested successfully and restriped.  After that was finished, I rebooted the system again and started getting volume scan errors.  And, my shares become unreachable.  RAIDar shows 6 happy disks and "healthy".  It shows, however, Volume C:  Offline, X-RAID2, 6 disks, 100% of 9292 GB used ( it only has about 4500 GB of data on it ).  I got the following:

Volume scan found errors that it could not easily correct. Please ensure that you have current backups of all valuable data before performing a full volume scan by rebooting the NAS through Frontview with the volume scan option enabled.

I also got the following ( cut and pasted from logs)

The paths for the shares listed below could not be found. Typically, this occurs when the ReadyNAS is unable to access the data volume. backup-Pro media-Pro

I did a reboot with full volume scan and check and fix quotas.  Got the same erros in log.  Got the following in email from the NAS:

An enormous email was sent out, attached. 

A second email cut and pasted below:

The paths for the shares listed below could not be found.  Typically, this occurs when the ReadyNAS is unable to access the data volume.

backup-Pro
media-Pro

[Sun Aug 16 11:34:06 CDT 2020]

At that point, I did a second reboot with volume scan and got the following:

***** File system check performed at Wed Aug 19 14:26:22 CDT 2020 *****
fsck 1.42.12 (29-Aug-2014)
/dev/c/c: Note: if several inode or block bitmap blocks or part
of the inode table require relocation, you may wish to try
running e2fsck with the '-b 32768' option first.  The problem
may lie only with the primary block group descriptors, and
the backup block group descriptors may be OK.

/dev/c/c: Block bitmap for group 44528 is not in group.  (block 0)


/dev/c/c: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options)

After a subsequent volume scan, I got the following by email:

***** File system check forced at Wed Aug 19 18:19:45 CDT 2020 *****
fsck 1.42.12 (29-Aug-2014)
e2fsck 1.42.12 (29-Aug-2014)
ext2fs_check_desc: Corrupt group descriptor: bad block for block bitmap
fsck.ext4: Group descriptors look bad... trying backup blocks...
/dev/c/c: recovering journal
fsck.ext4: unable to set superblock flags on /dev/c/c


/dev/c/c: ********** WARNING: Filesystem still has errors **********

So that is where I sit currently.  Neither of my volumes are accessible by any path.   I have CIFS, NFS, AFP, FTP, HTTP, and HTTPS services all active on frontview.  Health shows all disks as 'OK' .  I have used my NAS as a music system for years (logitech systems) and have ripped hundreds of CDs to it.  My music is the only thing I don't have a digital backup of.  I have all the disks though.  All the other data is backup of backups.  My main Mac Pro, backs up to disks for constant Time Machine with a second daily backup to an external disk via Cabron Copy cloner.  All of the family MacBook Pros are backed up to individual drives by Carbon copy cloner on a biweekely basis .  So , losing my data would not be the end of the world, but I would really like to have my data , especially my music , back intact. I would definitely consider the Netgear paid service if that is still available.

In the meantime, any advice would be helpful.

Regards,

Dale