2 quick questions on my RN104 OS6 screens

What firmware version are you running?
What device are you viewing the performance tab on, have you tried a different browser and clearing the cache on the browser?
On the System, Volumes tab, are all disks green and is the volume status normal, and are the disks' smart stats normal?
Have you done an OS reinstall?

The temperatures are reported by the disk via SMART. Are all the RN104 disks ST3000DM001? Or are there other models?

All the RN104's disks are ST3000DM001's, but 3 are 9YN166 (firmware CC9D,CC9E & CC4H) and one is 1CH166 (firmware just updated last nite from CC24 to CC29 hoping to fix this). Also, this same disk had some errors a few weeks back, but it only happened for a few days, and I haven't had any now for 2+ weeks.

Detected increasing reallocated sector count: [15448] on disk 4 (Internal) [ST3000DM001-1CH166, Z1F193GZ] 74 times in the past 30 days. This condition often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.

If disk4 has 15448 bad sectors, then it has failed and needs replacement. Anything with more than 50 reallocated sectors should be replaced.

Can you post the SMART stats on these disks?

Euphos,

Increasing reallocated sector normally due to the drive becoming faulty. It will be safe though but to make sure is to replace it. Before doing that, check your dirve if it is really getting faulty. Turn off you NAS. Connect your 4th drive to a computer and run the disk tool utility and check whether the drive is really faulty. If it is, then I suggest you replace it. Turn on the unit with all drives on it, then once your NAS is booted and everything is accessible, remove the faulty one and hot plug a new drive then let it sync (make take a few hours to complete). Make sure the new drive is either same size or bigger than the original "faulty" drive. :)

You did not say what the volume page says about your volume. The disk most likely has failed completely as StephenB pointed out.
I would say your situation is not safe, you need to replace the drive.
Make sure you have a backup of data on the Nas.
I think testing outside is reasonable where there is some doubt about the health of a disk. I think here it is fairly clear from your initial problem and the error count that the disk is dead or nearly dead.

vandermerwe wrote:
I would say your situation is not safe, you need to replace the drive.

Yes. And it is important to know the status of the other drives, which is why I requested the SMART stats on all of them.

I agree that a backup is urgently needed.

On testing, the only reason to test a drive with > 1500 bad sectors is if it is still under warranty and you want to get the failure code for the RMA.

Here's the S.M.A.R.T. info from (I'll try pasting it a couple of ways)

S.M.A.R.T INFORMATIONS
Name	Reallocated Sector Ct	Temperature	Start Stop Count	Power On Hours	Power Cycle Count	Load Cycle Count	Raw Read Error Rate	Seek Error Rate	Current Pending Sector	Offline Uncorr.
/dev/sda	20432	43.0 C	66	12316	65	92	146249384	4445709472	176	176
/dev/sdb	0	48.0 C	8	1287	8	8	153588496	13902723	0	0
/dev/sdc	0	51.0 C	237	13703	75	31234	101637304	134047933	0	0
/dev/sdd	0	46.0 C	414	19993	114	79451	199444304	8711338117	0	0

I started looking for some deals on new drives when I started seeing the error messages. Thinking of going with one of the WD Red Drives for a change. I'm going to need more space soon. I'm already down to less than 20% free. But, since all my other drives are 3TB, replacing one with a 4TB won't get me any benefit right now, correct? Don't I need to replace at least two drives with 4TB ones to gain additional space when using x-raid (raid5)?

Yes you would need at least two 4TB disks to see an increase in space. Replace one disk wait for it to finish resyncing etc. and for the volume to return to a redundant state then move on to the next disk.

Okay, I ended up ordering (2) x ST4000DM000 4TB drives for $315 delivered. I plan to obviously replace the one bad one (/dev/sda in slot #4). Is there another one that should be the next to be replaced? Or do I need to do one in the slot next to the other 4TB drive (ie /dev/sdb in slot#3)? The reason I ask, is the drive in slot #3 was just replaced about a month ago. The "Reallocated Sector Count" is zero for the other three. So all else being equal, I'd think I should replace either of the disks in Slot # 1 or #2 (/dev/sdc or /dev/sdd) with the other 4 TB drive. Will that work and give me ~1TB of extra storage? What's the formula for figuring it out?

As an aside, I believe the drives in Slots #3 & #4 were the ones I recycled from 2 Seagate GoFlex Home 3TB "NAS" units that I wasn't real happy with.