Readynas RN314 reshape hanging for days

I've been swapping out 3Tb for 6Tb drives on this unit for a few months.  One drive every few weeks.  Before I swapped the third drive, I upgraded the system to 6.6.1.  It rebooted and seemed fine, so I proceeded to swap out the third disk.  The previous 2 rebuilds took no more then 9 hours.  This third drive never showed the status on the LED, it always just flashed DEGRADED.  After a day, I logged in the admin interface only to see the rebuild at about 50% saying it had 2 days left.  After another day the web enterface stopped reponding.  Sshing to the host showed the volumes intact and a mdadm_reshape on eating 99% CPU.  I let it sit for another day or 2.  Still no change on the host, I tried to reboot it never shut down completely so I hard reboot it.

After it came back up, no data volumes were present and I recieved emails saying it was resyncing.  Logging onto the host I saw md127_raid5 process on top. 6-7 hours later, it showed complete, but still no data volumes mounted, and an md126_raid5 processes on top.  I tried running a few mdadm commands, but all seemed to hang.  I installed systat to see if any IO was happening, and very little was writing to the disk.  /proc/mdstat showed the. following, but never updated the status even though the md126_raid5 processes was at 99% for hours:

Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md126 : active raid5 sda3[4] sdd3[3] sdc3[5] sdb3[6]
8776243968 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/4] [U_UU_]
[>....................] reshape = 0.0% (0/2925414656) finish=16793708509.6min speed=0K/sec

md127 : active raid5 sda4[0] sdc4[1]
5860253824 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/2] [UU_]

md1 : active raid1 sda2[0] sdd2[2] sdc2[1]
523712 blocks super 1.2 [3/3] [UUU]

md0 : active raid1 sda1[4] sdd1[3] sdc1[5]
4192192 blocks super 1.2 [5/3] [U_UU_]

unused devices: <none>

I"ve tried rebooting, booting without newly added third disk.  Rebooting in "volume readonly" mode, and nothing seems to help.  I fear I've proded this system too much already, but I'm hoping to salvage my data.  Hopefully I haven't made it even more difficult to troubleshoot.  I'll include a number of commands on the system that may be helpfull.  I'd appreciate any input others may have to at least get me to a point where I can and export the data off this unit.  I'm new to mdadm utilities, but I'm fairly well experienced in linux in general.

the first odd dmesg errors:

[ 1199.754989] INFO: task md126_reshape:1383 blocked for more than 200 seconds.
[ 1199.755000] Tainted: P O 4.1.30.x86_64.1 #1
[ 1199.755004] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1199.755010] md126_reshape D ffff88007964bb38 0 1383 2 0x00000000

cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md126 : active raid5 sda3[4] sdd3[3] sdc3[5] sdb3[6]
8776243968 blocks super 1.2 level 5, 64k chunk, algorithm 2 [5/4] [U_UU_]
[>....................] reshape = 0.0% (0/2925414656) finish=20017759245.0min speed=0K/sec

md127 : active raid5 sda4[0] sdc4[1]
5860253824 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/2] [UU_]

md1 : active raid1 sda2[0] sdd2[2] sdc2[1]
523712 blocks super 1.2 [3/3] [UUU]

md0 : active raid1 sda1[4] sdd1[3] sdc1[5]
4192192 blocks super 1.2 [5/3] [U_UU_]

unused devices: <none>

mdadm --query --detail /dev/md126
/dev/md126:
Version : 1.2
Creation Time : Wed Jul 3 17:24:07 2013
Raid Level : raid5
Array Size : 8776243968 (8369.68 GiB 8986.87 GB)
Used Dev Size : 2925414656 (2789.89 GiB 2995.62 GB)
Raid Devices : 5
Total Devices : 4
Persistence : Superblock is persistent

Update Time : Sat Feb 4 13:20:00 2017
State : clean, FAILED, reshaping
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1

Layout : left-symmetric
Chunk Size : 64K

Reshape Status : 0% complete
Delta Devices : 1, (4->5)

Name : 7c6dfb8e:data-0 (local to host 7c6dfb8e)
UUID : 0c0fedf9:4770c7fd:19c55022:ee329eee
Events : 24712

Number Major Minor RaidDevice State
4 8 3 0 active sync /dev/sda3
6 8 19 1 spare rebuilding /dev/sdb3
5 8 35 2 active sync /dev/sdc3
3 8 51 3 active sync /dev/sdd3
8 0 0 8 removed

systemctl status readynasd
● readynasd.service - ReadyNAS System Daemon
Loaded: loaded (/lib/systemd/system/readynasd.service; enabled; vendor preset: enabled)
Active: activating (start) since Sat 2017-02-04 15:10:16 EST; 35s ago
Main PID: 14601 (readynasd)
Status: "Importing DB"
CGroup: /system.slice/readynasd.service
└─14601 /usr/sbin/readynasd -v 3 -t

Feb 04 15:10:16 NAS systemd[1]: Starting ReadyNAS System Daemon...
Feb 04 15:10:16 NAS readynasd[14601]: readynasd log started
Feb 04 15:10:16 NAS readynasd[14601]: readynasd started. (restarted=0)
Feb 04 15:10:16 NAS readynasd[14601]: DB (main) schema version: 23 ==> 23
Feb 04 15:10:16 NAS readynasd[14601]: DB (queue) schema version: new ==> 0

Any help would be apreciated.  Thanks.

Carl