ReadyNAS - Remove inactive volumes to use the disk. Disk #1,2.

Just in case anyone is searching for this error and wants to know one (of possibly numerous) of the reasons for the error and the solution...

I contacted NETGEAR Support and requested help. They were very helpful, diagnosed the issue, suggested a couple of solutions, and all in all I'd recommend them.

Situation

I set up my RN316 a few days ago under the (then current) firmware 6.7.3.

X-RAID2 setup (one of the reasons I wanted this NAS was to use different sized drives).
The drives were all put in at once:
2x 2GB (Ch 5 & 6), 2x 3GB (Ch 3 & 4), 2x 4GB (Ch 1 & 2)
Although it took 26 hours to get all the disks sorted out [edit: reshape], the NAS seemed to be working fine, I only had a small amount of test data on it.

I updated the firmware last night to 6.7.4, thinking the right time to do so was
a) when there was little data on the drives, and
b) when there wasnt any data to lose, and
c) to see how seamless NetGears firmware updates were in a low risk situation, and
d) to get the RN316 onto the latest firmware.

Now I show a similar error to tom72.
- I can access the NAS local admin page at 10.0.1.xx in a browser OK.
- all six HDDs show as red in System/Volumes
- I now have a warning saying "Remove inactive volumes to use the disk. Disk #1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 1, 2"
- instead of a single summary box on the left hand side of the System/Volumes page, one that previously showed my working setup, I now have two boxes. The top one has Data = 0, Free Space = 0, Type = RAID 5. The Bottom one has Data = 0, Free Space = 0, Type = RAID Unknown.
- whenever I try and use any other tab, a warning pops up saying "No volume exists. NETGEAR Recommends that you create a volume before configuring others. Navigate to the System > Volumes page to create a volume."

Im pretty glad I had the opportunity to do a firmware update when nothing important was on the NAS.

I provided system logs, screenshots etc, similar to those above in this thread.

Diagnosis

From NETGEAR Support:

Upon checking the logs, it seems that HDD inserted on channel 5 with serial number S2HGJD2Z805484 is now getting faulty due to number of errors.

This is the only reason why you encountered this issue on you device.

You can try to remove this disk and error should disappear, your NAS is on RAID 5 configuration and it has one drive fault tolerance.

You just need to replace your faulty drive to fix the issue.

Please see list of recommended and tested drives for your NAS.

My next actions

I shut down the NAS.

I replaced the faulty 2GB HDD with a fresh 4GB HDD, formatted exactly the same as the other HDDs.
I inserted the replacement disk, and turned the power on at about 930PM.

At 800AM the following morning the NAS was still stuck at "Booting..." on the front panel of the RN316.

I could not reach the local admin page through my browser.

What I should have / could have done

Turns out I should have shut down, removed the faulty HDD, and rebooted without any drive in the slot.

After booting, I should then have hot-plugged in the new drive (ie. while the NAS is powered-on, insert the replacement drive to the NAS).

The NAS should then resync automatically.

Alternatively I could have performed a factory reset, since there was no data on the NAS.

What I actually did to solve the issue

Due to time zone differences, and me being somewhat impatient to get going, I did a factory reset.

[As an aside, Interestingly, the RN316 wouldn't factory reset with the new drive inserted.

To get the NAS to factory reset I had to remove the new drive (so, only 5 of the 6 original HDDs were in the NAS),  and then factory reset as per the manual for the RN316.]

After the factory reset (with 5 of 6 drives in place) the RN316 resynced with just the 5 drives. This took about a day, which was about what I expected.

After the resync with 5 drives was complete, I inserted the new drive.

As the old (faulty) HDD was 2TB, and the new HDD was 4TB, it then took about another day to add the 6th HDD to the array, as a reshape was required.

I now have a working 6 HDD array, as per the screenshot below:

Cheers to those who gave their time and assistance in the thread above. Hopefully this is of some help to later searchers for this error, although please note there may well be plenty of other reasons for the error, so one size may not fit all!