I have a ReadyNAS NV+ v2 (arm) running 5.3.13 with 3 WD Red 2TB disks.
Disk2:
WDC WD20EFRX-68AX9N0 1863 GB (27 °C / 80 °F, Write-cache On). Status: OK
Disk 3:
WDC WD20EFRX-68EUZN0 1863 GB (27 °C / 80 °F, Write-cache On). Status: OK
Disks 1 & 2 are the oldest and Disk 3 was added later to expand storage.
Early this week the ReadyNAS became unresponsive; streaming stopped and it would not respond to the front panel when I tried to shut it down.
In the end I had to unplug power.
When I brought it back up the LCD reported Disk 1 Failure.
I ejected Disk 1 for inspection.
Again the system and front panel was unresponsive.
While waiting for my replacement WD Red 2TB (see below) I was worried that the NAS may be faulty, so I power cycled and brought it up without Disk 1. The LCD reported: C: Unprotected.
There is nothing about disk failure, unprotected status, in the logs.
I hot inserted the replacement Disk 1:
WDC WD20EFAX-68B2RN1 1863 GB (22 °C / 71 °F, Write-cache On). Status: OK
and it is showing status green but the Volume is still flashing yellow 15 hours later. I only have about 1.1TB of data.
The LCD is still reporting: C: Unprotected Only '2' and '3' are lit on the front panel. '1' is still unlit.
The NAS has been online since the reboot with only disks 2 and 3.
There is nothing in the logs about resynchronisation, disk insertion, anything.
RAIDar shows 3 disks with green ticks and repeats the message: Status: Volume C: Raid Level X2, Not Redundant. A disk failure will render this volume dead. All advice appreciated.
You could just wait longer, but personally I would exchange the disk for a WD Red Plus (WD20EFRX) or a 2 TB Seagate Ironwolf. Both are CMR drives.
FWIW, the amount of data isn't relevant to resync time. Every sector on the replacement disk is written (and every sector on the remaining disks is read).
Darn, I thought I was replacing like with like. When I bought the original two WD Red and even the later third WD Red, they were just WD Red, not WD Red Plus.
In fact, the replacement disk did not solve my problem; which has gotten worse.
After a long period of inactivity, I shut down the system and tested the (external) power supply and found it unstable (varying from 12.4v to 13.7v).
By the time I got a replacement power supply my data volume has dissapeared, despite RAIDar saying my system is 'Healthy'.
All 3 (original) disks look reasonable (I think). The suspected disk 1 does have a Raw Error Read Rate of 617 and Current Pending Sector of 23.
By way of testing the system with new power supply, I set the 3 original disks to one side and used the replacement disk (which never made it into the original RAID) to set up a fresh RAID0 system; which worked fine.
I have mdadm --detail output for /dev/md0 and /dev/md1, both showing 'State : clean, degraded', but I do not understand the details.
I am reading up to see if it is possible to get my data back via mdadm with a fallback of buying RAID recovery software for my son's tower PC (but I believe it has hardware RAID; which may not be the right thing).
