Ultra 6 configuration question

imahawki wrote:
I would like to buy an Ultra 6 and configure it with two separate pools of 3 disks. One as live data and the other as backup. The reason I want the pools separated is because I want the 3 drives that are the backup to be able to be swapped out. So, will this work?

That's not recommended as the SATA connectors are not rated for constant swapping. It's better if you consider something like http://www.readynas.com/replicate .

While in theory it sounds like a good idea, I don't think it will work the way you expect.

You can configure the device for 2 separate raid-5 ararays of 3 disks each, this is not a problem. You simply factory reset and choose FLEX-RAID mode from RAIDAR and you configure the volumes however you wish.

The problem comes when you decide you want to pull the 3 disk 'backup' volume.
Readynas boots from the installed disks, not from an onboard flash or anything like that, so removing half the disks from the system will very likely prevent booting in the first place.

Even if the system boots with the primary 3 disk raid, once the other 3 disks are removed, they will be considered 'dead'.

If you put the previously removed 3 disks back in at some point later, the system should treat them as new disks (because they are out of sync with the main 3 disk raid). Even though the DATA volumes are not related and not sync'd in any way, the SYSTEM partitions are no longer in sync.

I would suspect the only way to boot from the 'backup' 3 disks is to remove the first 3 disks and only boot from the last 3 (assuming it will even boot with 50% of the disks removed).

This means once you do the initial sync between primary volume, and backup volume, once you remove the backup volume, you would no longer be able to have both sets in the device at the same time. Once you break the set by removing the backup volume disks, you could only boot from one set or the other, not both.

Long story short, don't remove the backup volume disks, its a bad idea.

If you simply leave all the disks in place, your strategy will probably be ok (as long as you do not get 2 disk failures in the same volume set, at the same time).

In my opinion, you would be far better off using all 6 disks in DUAL REDUNDANCY mode and continuing to backup off site with USB disks.

You might want to consider two Ultra 4 units. One would be your main server so the data would be accessible by any computer on your home network at any time without having another PC on all the time. The second could be set up to update it's data from the first using rsync (after the initial backup job running NFS). Then you could back up your critical/important data to an external drive on a periodic basis as you are doing now (similar to what I was doing, maintaining a baclup Passport in my desk - now a bank SD box since I've retired).

Remember - never trust your data to only one device. If you take digital photos, don't erase them from the camera until you have backed up the images on your PC for example. Redundancy in an NAS (single or double) is intended to be able to recover from a disk failure easily, it s NOT a backup plan.

I was seriously searching as you were about 18 months ago and considered the Pro, but wound up with two NVX units (replaced by the Ultra 4) for about the same price. Last night I came home from a trip, plugged in and turned on my UPS which then proceeded to power up my equipment (router, switch, modem, two NVX units and a printer which should not be on the circuit). My backup unit powered up normal, but my main one sat there with the fan running and no lights. First thought - unprintable. Second thought, I can run off the backup unit while I am working on the primary (I also do this when upgrading units), third thought try again. Unplugged it, plugged it back in and it powered up just fine. Apparently both units and the printer draw too much juice for them all to power up together.

Point is - I have no worries about my data's security since going to two units, one NAS backing up to another nightly. And with 3TB disks, you have a current max of 8.1TB (net after overhead) of volume on any one device. That is a lot of movies, for I don't think your critical files will be anywhere near that (mine are about 150GB).

Thanks guys! Appreciate the honest feedback!