Hello! My PR4100 seems to be in a state where it’s deleting data; maybe someone in here can tell me how i can stop that. 
Here is how i got here: I wanted to upgrade my 4x4TB RAID 5 to 4x12TB, so I did that by going through the “expand capacity” process in the Raid Menu. Swapping the drives and rebuilding them took a while but it went pretty smoothly. Then it got stuck on “wait to resize” for almost a week.
The size of the Raid hadn’t changed yet but I was able to access the data again. But when I compared a folder to one I had backed up earlier I found out that files were missing. Since I wasn’t too happy with the PR4100’s network speed anyway I then planned to get a completely new NAS and use the 12TB drives with that instead. So I shut down the NAS, took them out and put the original drives back in. This might have been a mistake. 
After reboot it looked fine at first. But then I got a “Alert: Volume Degraded” email and noticed that the amount of free space was going up. I checked the Raid status and it said “resizing”. So I turned it off.
So… how do I fix this? Can I just reload the default configuration? Will I be able to access my data after that and can I recover the lost files?
Any help on this is highly appreciated! Thanks!
Thanks for the help. Here are the results:
root@wdNAS ~ # smartctl --smart on --info /dev/sda;
smartctl 7.2 2020-12-30 r5155 [x86_64-linux-4.14.22] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red
Device Model: WDC WD40EFRX-68N32N0
Serial Number: WD-WCC7K0TNY8PZ
LU WWN Device Id: 5 0014ee 26725e5b4
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Form Factor: 3.5 inches
Device is: In smartctl database [for details use: -P show]
ATA Version is: ACS-3 T13/2161-D revision 5
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Dec 4 13:22:56 2023 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF ENABLE/DISABLE COMMANDS SECTION ===
SMART Enabled.
root@wdNAS ~ # smartctl --smart on --info /dev/sdb;
smartctl 7.2 2020-12-30 r5155 [x86_64-linux-4.14.22] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red
Device Model: WDC WD40EFRX-68N32N0
Serial Number: WD-WCC7K4HFZDJL
LU WWN Device Id: 5 0014ee 26725e6ee
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Form Factor: 3.5 inches
Device is: In smartctl database [for details use: -P show]
ATA Version is: ACS-3 T13/2161-D revision 5
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Dec 4 13:23:53 2023 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF ENABLE/DISABLE COMMANDS SECTION ===
SMART Enabled.
root@wdNAS ~ # smartctl --smart on --info /dev/sdc;
smartctl 7.2 2020-12-30 r5155 [x86_64-linux-4.14.22] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red
Device Model: WDC WD40EFRX-68WT0N0
Serial Number: WD-WCC4E3J4XCEC
LU WWN Device Id: 5 0014ee 25ff502c2
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ACS-2 (minor revision not indicated)
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Dec 4 13:24:36 2023 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF ENABLE/DISABLE COMMANDS SECTION ===
SMART Enabled.
root@wdNAS ~ # smartctl --smart on --info /dev/sdd;
smartctl 7.2 2020-12-30 r5155 [x86_64-linux-4.14.22] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red
Device Model: WDC WD40EFRX-68WT0N0
Serial Number: WD-WCC4EHAH8UJD
LU WWN Device Id: 5 0014ee 2b54b0cc5
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ACS-2 (minor revision not indicated)
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Dec 4 13:25:27 2023 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF ENABLE/DISABLE COMMANDS SECTION ===
SMART Enabled.
root@wdNAS ~ # cat /proc/mdstat;
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md1 : active raid5 sdb2[1] sdd2[3] sdc2[2]
11708466624 blocks super 1.0 level 5, 64k chunk, algorithm 2 [4/3] [_UUU]
bitmap: 8/8 pages [32KB], 262144KB chunk
md0 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0]
2094080 blocks super 1.2 [4/4] [UUUU]
bitmap: 0/1 pages [0KB], 65536KB chunk
unused devices: <none>
root@wdNAS ~ # mdadm --detail /dev/md1;
/dev/md1:
Version : 1.0
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 3902822208 (3722.02 GiB 3996.49 GB)
Raid Devices : 4
Total Devices : 3
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Dec 4 13:26:48 2023
State : clean, degraded
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
Consistency Policy : bitmap
Name : 1
UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Events : 24352
Number Major Minor RaidDevice State
- 0 0 0 removed
1 8 18 1 active sync /dev/sdb2
2 8 34 2 active sync /dev/sdc2
3 8 50 3 active sync /dev/sdd2
root@wdNAS ~ # mdadm --examine /dev/sda2;
/dev/sda2:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Name : 1
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 7805644528 (3722.02 GiB 3996.49 GB)
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 7805644416 (3722.02 GiB 3996.49 GB)
Super Offset : 7805644784 sectors
Unused Space : before=0 sectors, after=368 sectors
State : clean
Device UUID : 8dd4f833:af5d7e63:1a72ba82:b01cc1f9
Internal Bitmap : 2 sectors from superblock
Update Time : Sat Nov 25 11:40:21 2023
Checksum : 6dc690a - correct
Events : 2517
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)
root@wdNAS ~ # mdadm --examine /dev/sdb2;
/dev/sdb2:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Name : 1
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 7805644528 (3722.02 GiB 3996.49 GB)
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 7805644416 (3722.02 GiB 3996.49 GB)
Super Offset : 7805644784 sectors
Unused Space : before=0 sectors, after=368 sectors
State : clean
Device UUID : 8ca85999:7df781da:96afc30d:53fe989b
Internal Bitmap : 2 sectors from superblock
Update Time : Mon Dec 4 13:28:49 2023
Checksum : 102f4235 - correct
Events : 24360
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 1
Array State : .AAA ('A' == active, '.' == missing, 'R' == replacing)
root@wdNAS ~ # mdadm --examine /dev/sdc2;
/dev/sdc2:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Name : 1
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 7805644528 (3722.02 GiB 3996.49 GB)
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 7805644416 (3722.02 GiB 3996.49 GB)
Super Offset : 7805644784 sectors
Unused Space : before=0 sectors, after=368 sectors
State : clean
Device UUID : f87c55ba:30c52ab4:21747312:df91665d
Internal Bitmap : 2 sectors from superblock
Update Time : Mon Dec 4 13:29:19 2023
Checksum : d1513c8b - correct
Events : 24362
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 2
Array State : .AAA ('A' == active, '.' == missing, 'R' == replacing)
root@wdNAS ~ # mdadm --examine /dev/sdd2;
/dev/sdd2:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x1
Array UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Name : 1
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 7805644528 (3722.02 GiB 3996.49 GB)
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 7805644416 (3722.02 GiB 3996.49 GB)
Super Offset : 7805644784 sectors
Unused Space : before=0 sectors, after=368 sectors
State : clean
Device UUID : 40b89dab:8ff3ded5:d81f62ef:808b1f09
Internal Bitmap : 2 sectors from superblock
Update Time : Mon Dec 4 13:29:50 2023
Checksum : 6cf54bad - correct
Events : 24364
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 3
Array State : .AAA ('A' == active, '.' == missing, 'R' == replacing)
Also after restarting now all the drive LEDs are red and the display says “RAID roaming enabled”
root@wdNAS ~ # mdadm --add /dev/md1 /dev/sda2;
mdadm: added /dev/sda2
root@wdNAS ~ # cat /proc/mdstat;
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md1 : active raid5 sda2[4] sdb2[1] sdd2[3] sdc2[2]
11708466624 blocks super 1.0 level 5, 64k chunk, algorithm 2 [4/3] [_UUU]
[>....................] recovery = 0.2% (9653372/3902822208) finish=437.6min speed=148266K/sec
bitmap: 8/8 pages [32KB], 262144KB chunk
md0 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0]
2094080 blocks super 1.2 [4/4] [UUUU]
bitmap: 0/1 pages [0KB], 65536KB chunk
unused devices: <none>
root@wdNAS ~ # mdadm --detail /dev/md1;
/dev/md1:
Version : 1.0
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 3902822208 (3722.02 GiB 3996.49 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Dec 4 13:55:59 2023
State : clean, degraded, recovering
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 64K
Consistency Policy : bitmap
Rebuild Status : 0% complete
Name : 1
UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Events : 24512
Number Major Minor RaidDevice State
4 8 2 0 spare rebuilding /dev/sda2
1 8 18 1 active sync /dev/sdb2
2 8 34 2 active sync /dev/sdc2
3 8 50 3 active sync /dev/sdd2
Awesome! Thank you so much! I’ll be more cautious in the future, I promise! 
Well, that’s not too bad.
Oh, one more thing: In the storage section it still says “expanding”? Do you think this is gonna be a problem?
Yeah, I’ll definitely do backups after the rebuild has finished…
Again, thanks for your help! I’ll follow up with the results of the rebuild in a few hours.
Looks like it worked.
root@wdNAS ~ # mdadm --detail /dev/md1;
/dev/md1:
Version : 1.0
Creation Time : Tue Nov 26 16:28:44 2019
Raid Level : raid5
Array Size : 11708466624 (11166.06 GiB 11989.47 GB)
Used Dev Size : 3902822208 (3722.02 GiB 3996.49 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Tue Dec 5 00:47:04 2023
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
Consistency Policy : bitmap
Name : 1
UUID : d3d455a8:7a1bf2d7:96ab1313:e28f5d7f
Events : 32989
Number Major Minor RaidDevice State
4 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
2 8 34 2 active sync /dev/sdc2
3 8 50 3 active sync /dev/sdd2
Dashboard still says “expanding” and wants me to swap out drive 1 now. 
Another problem is now that I can’t access one of my shares via SMB or FTP. I checked via SSH and all the files are there though. Permissions seem fine too. Is there an easy way to find out what the problem is? Or should I just add a new share and copy the files over manually?
