10TB with USB expansion on Duo V1 possible?

Possible yes.
Performace is probably going to be less than satisfactory unless you're just using the USB drives for data hat you don't access a lot. I think if you are accessing the usb drives a lot this may be a problem, although I don't have exact read/ wite performance data.
Data wil be at risk unless you have everything backed up somewhere else.
It sounds like you need a larger NAS.

Data on the duo is definitely at risk. When either internal drive fails, the entire 4 TB array will completely lost. It would be wise to rebuild the duo with 2 volumes (one for each drive). Or go with RAID-1. As vandermerwe points out, you should have a backup strategy.

A better way to reach the 10 TB goal would be buy a new RN104, and start with 3x3TB drives. Then the combined storage of the duo and the RN104 would be ~ 10TB. IF you are ok without raid-5, you could get by 2x3TB jbod (and could potentially substitute an RN102). But the RN104 seems like a better approach - it can be expanded to 15-20 TB of storage with 4 TB drives, and we should see 5 TB drives coming out over the next year or so.

Adding another NAS wil give better performance and more reliability than stringing USB drives onto the duo.

Thanks to both of you. I appreciate the responses.

The backup is not a concern to me. (I pay for a large dropbox account and keep critical files backed up that way.) The readynas is now used strictly as a media server - and if I lose that media, it is not the end of the world. I have streamed HD media off an attached USB drive before and even wirelessly - the Duo is snappy enough to do that. The RN104 would be nice, it actually looks like a great NAS. I just wanted to know whether the 10TB was theoretically possible and it seems that it is.

I'm facing this decision now because one of my seagate 5900 LP "click of death" drives just failed. The other one is working well, but who knows for how long. I am going to take this opportunity to replace that drive with WD REDs, and attach the remaining working 5900LP drive as USB. If I want to expand later on, I could either get another NAS or add a couple more 2TB drives up to 10TB.

betty

You will either need to clone the failing drive (with the NAS off) or destroy the existing volume. Replacing the drive w/o that requires xraid or raid-1.

If you do destroy the volume, I would definitely go with a two-volume approach (one for each drive).

Will definitely do the two volume approach. Thanks for the advice. As I understand it, I run through the following procedure:

1. Back up files from current drive to an external drive connected to my pc.
2. Add new drive 1 to bay 1 and set up raid 0.
3. Shut down readynas
4. Add new drive 2 to bay 2 and boot up readynas
5. go to add volumes and create as raid0.

Correct?

Thanks again!
betty

With the existing drives, you can simply delete your current volume, and just create new ones (you still need to restore from backup btw). No need to shut down, etc.

If you are using new drives, I suggest

1. Back up files from current drive to an external drive connected to my pc.
2. Shutdown NAS and remove old drives. Insert disk 1 into drive 1
3. Power up readynas, which will start a factory reset. Use RAIDar within 10 minutes to choose flexraid. Select Raid 0
4. Wait for NAS to complete setup
5. Add new drive 2 to bay 2 (no need to power down)
6. go to add volumes and create as raid0.
7. Restore data.

You will need to balance the storage yourself between the two volumes - that is the disadvantage. So note the approximate amount of data in each share. When I've done this, I also think about the growth rates - I don't want to put all the growing shares on the same volume.

Very helpful! Thank you!

When you say "growth rates," you mean the rate at which I am adding data to each drive, correct? That should'nt be too tough to manage.

Thanks again. I'm looking forward to implementing this system with my trusty duo v1.

betty23 wrote:
When you say "growth rates," you mean the rate at which I am adding data to each drive, correct? That should be too tough to manage...

Basically yes. My music library grows slowly, my video library grows more quickly,... Since rebalancing the storage requires moving shares between the volumes, it is a mild nuisance. So I try not to put all the rapidly growing shares on the same volume, because I don't want to do it very often.

Don't over-think it, it's just a suggestion that you spend a couple minutes working out what shares you place on what volumes.