NAS104 Raid decision? Xraid vs Raid 10 etc #24296869

It still says 39 hours. What the heck does this thing do for that long? It can't possibly take that long to format the drives. Is this process longer for Raid 6?

Is something else happening on the NAS?

StephenB wrote:
Is something else happening on the NAS?

Nope, nothing. I just spoke with Netgear. A very painful support call.

After the first 2 agents told me 55 hour initialization times were normal, the second escalated rep said it shouldn't take more than 6-8 hours. It surprises me that even if it was 6 hours that they have no documentation indicating or warning the customer of these abnormally long times.

I get the sense from speaking with these support reps that this product is truly only meant to be run in Xraid. That is what they all consistently recommended. As ridiculous as this sounds, I got the impression from them that the other raid implementations are not optimized and more gimmicks than real options.

So far I am very disappointed. For me this was a substantial investment. I would not have made it if the device really underperforms like this. Why would they even bother with the other raid options if they don't perform adequately. They are looking at logs and I opened support ssh mode for them, hopefully there is something that can be fixed. In the meantime, my brand new drives are now getting a lot of wasted I/O cycles which I can never get back.

Your 20 hour RAID-10 initialization seems more typical. I've gotten about 12 hours when I've replaced a 3 TB drive in my pro-6. I haven't initialized with RAID-6 - in principle the RAID mode shouldn't matter much, since the two parity blocks are always the same, so they don't need to be recomputed. Though if they are computed over and over, it likely will take somewhat longer. Note that RAID initialization requires all sectors in the volume to either to read or written (even if they are not in use).

XRAID is standard RAID-1 or RAID-5 (if disks are different sizes, then some layers are RAID-5 and others are RAID-1). So optimizing XRAID means optimizing both those modes.

RAID-6 isn't a gimmick, and there are netgear folks here (mdgm for one) who frequently recommend it. Though usually folks are using it on x86 platforms like the ultra, pro, RN300 or RN500. Initialization is rare, the benchmark afterwords is more useful for understanding performance.

On the performance side, the write penalty in the original review was mostly due to the btrfs copy-on-write. That increases data safefy. Otherwise write speeds for RAID-1 should be about the same as read speeds.

What did you see with RAID-10 btw?

StephenB wrote:

Your 20 hour RAID-10 initialization seems more typical. I've gotten about 12 hours when I've replaced a 3 TB drive in my pro-6. I haven't initialized with RAID-6 - in principle the RAID mode shouldn't matter much, since the two parity blocks are always the same, so they don't need to be recomputed. Though if they are computed over and over, it likely will take somewhat longer. Note that RAID initialization requires all sectors in the volume to either to read or written (even if they are not in use). XRAID is standard RAID-1 or RAID-5 (if disks are different sizes, then some layers are RAID-5 and others are RAID-1). So optimizing XRAID means optimizing both those modes. RAID-6 isn't a gimmick, and there are netgear folks here (mdgm for one) who frequently recommend it. Though usually folks are using it on x86 platforms like the ultra, pro, RN300 or RN500. Initialization is rare, the benchmark afterwords is more useful for understanding performance. On the performance side, the write penalty in the original review was mostly due to the btrfs copy-on-write. That increases data safefy. Otherwise write speeds for RAID-1 should be about the same as read speeds.

I understand that an actual rebuild after a failure is a very different and intense process. I don't understand why the initialization should take any longer than a full format.

I know it isn't a gimmick, I just mean their implementation is not good enough to merit it's use.

StephenB wrote:
What did you see with RAID-10 btw?

Well I was going to wait until I had more data on the other modes, but here it is. Pretty embarrassing performance.

Just to reiterate I am using a NAS104 with 4 3TB Western Digital Red drives. I first updated my firmware to 6.2 before I did anything.
I am using no encryption and no anti-virus.
I am using a wired connection via a 100mb switch that both the computer and drive is plugged into with nothing in between. I am testing using a windows file write on a mapped network drive of a share. This is raid 10. I tried with 3 different file sizes. Pretty consistently bad.

NAS performance tester 1.7 http://www.808.dk/?nastester
Running warmup...
Running a 100MB file write on Z: 3 times...
Iteration 1: 11.79 MB/sec
Iteration 2: 11.78 MB/sec
Iteration 3: 11.80 MB/sec
-----------------------------
Average (W): 11.79 MB/sec
-----------------------------
Running a 100MB file read on Z: 3 times...
Iteration 1: 11.73 MB/sec
Iteration 2: 11.82 MB/sec
Iteration 3: 11.84 MB/sec
-----------------------------
Average (R): 11.80 MB/sec
-----------------------------
Running warmup...
Running a 400MB file write on Z: 3 times...
Iteration 1: 11.84 MB/sec
Iteration 2: 11.81 MB/sec
Iteration 3: 11.82 MB/sec
-----------------------------
Average (W): 11.82 MB/sec
-----------------------------
Running a 400MB file read on Z: 3 times...
Iteration 1: 11.75 MB/sec
Iteration 2: 11.82 MB/sec
Iteration 3: 11.84 MB/sec
-----------------------------
Average (R): 11.80 MB/sec
-----------------------------
Running warmup...
Running a 2000MB file write on Z: 3 times...
Iteration 1: 11.81 MB/sec
Iteration 2: 11.81 MB/sec
Iteration 3: 11.81 MB/sec
-----------------------------
Average (W): 11.81 MB/sec
-----------------------------
Running a 2000MB file read on Z: 3 times...
Iteration 1: 11.82 MB/sec
Iteration 2: 11.77 MB/sec
Iteration 3: 11.78 MB/sec
-----------------------------
Average (R): 11.79 MB/sec
-----------------------------

You are at the limit of your 100 mbit connection. 11.8 MB/sec -> 94.4 mbits.

Not sure what you expected, but to go faster you need gigabit.

StephenB wrote:
You are at the limit of your 100 mbit connection. 11.8 MB/sec -> 94.4 mbits. Not sure what you expected, but to go faster you need gigabit.

Hmmm... This might be correct.

Well I will let you know what they say about the rebuild issue. It still says I have 34 hours to go.

Still building....Netgear isn't exactly communicating much. They are telling me that their engineers have opened an issue and they believe that there is a bug in the firmware. I have requested more information, but it is like pulling teeth. So I am just sitting tight listening the my drives work.

A rebuild is required to sync the drives sector by sector to setup the RAID.

Do you have a case number?

Still building....Over 2 days now!

case #24296869
So far all they have given me is a vague answers and lots of waiting on hold. However, I think they have been doing something they just don't seem to be communicating what.