New 316 (diskless) and upgrading to 6.2 before I start

You will need to initially setup your RN316 with at least one drive inserted. After it has been initially setup, then you may either do an automatic or manual update of the firmware to v6.2.0.

You may start with your 2x6TB disks and you may add drives later one-at-a-time with XRAID.

With XRAID, if ever you will be adding 2 more drives one-at-a-time, it will have an XRAID-RAID5 type config and of course that's single redundancy.

If you want dual-redundancy, here are the steps:

1. You have started with 2x6TB disks initially with XRAID. Just add another 1x6TB and let ther resync process complete. This will be an XRAID-RAID5 type config and of course it has single parity.
2. Once the resync process has completed, turn off XRAID. You will now be on FLEX-RAID.
3. Insert the another 1x6TB then select the option to Add Parity.
4. You could switch back to XRAID or remain at FLEX-RAID.

Thank you! That is exactly what I needed to know.

In step 4, if I switch back to XRAID I'm assuming that if/when I added a 5th 6TB drive it would auto expand, giving me another 6TB of space with dual-redundancy.

Yup! it should provide you with additional storage capacity.

So I have the two drives in, is it normal for the syncing/rebuilding to take 12+hours for 2 new/blank disks?

bdl99 wrote:
So I have the two drives in, is it normal for the syncing/rebuilding to take 12+hours for 2 new/blank disks?

On my pro-6 it usually takes about 10-12 hours to resync a 3 TB drive (using xraid/RAID-5).

Though you might think that syncing/building an empty volume should be faster than a full one, that is not the case. RAID is between the physical storage and the file system. So even if the file system is empty, it still requires rewriting every sector in the volume. And replacing a drive also requires reading every sector of the remaining drives, and writing every sector of the new one.

StephenB wrote:

bdl99 wrote: So I have the two drives in, is it normal for the syncing/rebuilding to take 12+hours for 2 new/blank disks? On my pro-6 it usually takes about 10-12 hours to resync a 3 TB drive (using xraid/RAID-5). Though you might think that syncing/building an empty volume should be faster than a full one, that is not the case. RAID is between the physical storage and the file system. So even if the file system is empty, it still requires rewriting every sector in the volume. And replacing a drive also requires reading every sector of the remaining drives, and writing every sector of the new one.

Thanks, makes sense when you think about it that way.

I have just started this process with my RN316. It took about 12 hours to build my X-Raid array consisting of 5 x 4TB WD F9YZ disks after upgrading to OS6.2. I then turned X-Raid off and added the 6th disk. I then selected the option to add parity. The RN316 is now busy rebuilding the array. What concerns me is that the unit is reporting that this will take 206 hours. Is this correct, or should I suspect this duration will drop once the unit gets up to speed?

When switching from Xraid to flexraid and then back again for the purposes of changing to dual redundancy, it is not necessary to wait for resyncs to complete between each switch from Xraid -flexraid and flexraid-Xraid. The resync can be allowed to complete at the final stage when back in Xraid.
206 hours is too long, but I'd wait for about 6 hours or so to see if this comes down. You don't have encryption do you?
If it doesn't come down, I'd check all the disks using vendor tools.

It almost always completes much faster than the estimate, but probably will take longer than the original 12 hours. All the data is being shifted around to create space for the "Q" parity blocks, which are being computed and written. If you look at the pictures for raid-5 and raid-6 here you will get some sense of the work involved: http://en.wikipedia.org/wiki/Standard_RAID_levels

It is a low-priority background process, so if the NAS is doing other stuff it will take longer than if it is otherwise idle.

Leave it overnight at least before you panic.

Thanks for the feedback.

I waited for the initial X-Raid Raid 5 build to complete before switching to Flex-Raid and adding the new disk. I then started the rebuild and switched back to X-Raid. The unit has continued the rebuild overnight. It has been churning away for 12 hours and has completed 5.89% of the rebuild. It is still reporting that the process will take more than 200 hours. I'm not doing anything else with the unit at the moment and will wait until the rebuild is finished before adding data.