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[Jones Max]

Hello, here is an interesting question

I have 2x WD20EADS 2TB Western Digital drives (the non advanced format older types) in my DNS-323. Drives are setup in RAID 1 Mirror and everything is fine.

I keep a full copy of all my data on my PC. That data it is all backed up to the DNS-323 which is mirrored so I really have 3 copies of data.  1 copy in the PC and 2 copies in the DNS-323 because of RAID 1. I don't like this setup and feel that one drive is basically going to waste so I want to remove one drive and use the DNS 323 with 2 single drives insted of RAID. I have 2 DNS 323s. I'm ok with 2 copies of data which is one in my PC and 1 in a NAS on a single drive.

So if I remove 1 drive and place it in another DNS-323 with same firmware will I have to format the drive or will it work with data intact? Can I set it up to run as 2 single drives without losing data?

I think the drive in DNS-323 number 1 will continue to function normally until I place another drive in it in the future. When I do that can I format the new drive as a single drive keeping the data intact on the original drive?

Follow me?  Sorry long day and my brain is tired 

[fordem]

First - you can move from a RAID1 configuration to standard volumes without destroying the data.

Start by verifying the status to be sure the RAID array is not degraded, and then power down the DNS-323 and remove one of the drives.  Power the unit back up, log into the admin page, select TOOLS/RAID and then set the RAID type to standard volumes and format the drive, when this has completed, power the system down and reinsert the drive that you removed earlier.

Power the system back up and check the status it should you both drives, and you should still be able to access the data.

Now - having answered your question - let me raise a couple of points with you.

My DNS-323 is used like yours is - it's in a RAID1 configuration, and used for backup, a task previously handled by a DDS5 tape drive.  I don't know if you've ever used tape (or any other removable media drive), but if you haven't, trust me disk-to-disk (D2D) backup beats it hands down, it's way faster and there's no waiting around to change media - but it's not without it's challenges.

When using tape as a backup medium, most people use some sort of rotation scheme - grandfather, father, son is probably the simplest & best known - this allows you to keep a copy off site, and you have multiple copies in case one becomes damaged or corrupt.

More important, if the tape drive failed, you have the ability to replace the drive and simply insert the tape to gain access - D2D backup does not allow this.

You can create multiple D2D tragets and run rotation schemes like grandfather, father, son to the individual targets, but if your single backup drive fails, it's taking your data with it.

The choice is yours - what's the probability of having two drives fail simultaneously?  Do you really need more than one backup - some people think they do - me included.

[gunrunnerjohn]

FWIW, I have a total of three NAS units that all our systems backup to.  The primary one has My Documents for several of the laptops so that they are available from more than one computer.

Every week the primary NAS backs up completely to a secondary NAS.  Every other week, the secondary NAS backs up to the 3rd NAS.

This gives me several weeks to recognize issues on the primary before backups are gone.

In addition to that, my desktop computers all have multiple hard disks, and they make frequent backups to the separate physical drive of important files and O/S images.

Just because you're paranoid, it doesn't mean they're not out to get you!

[Jones Max]

Fordem, I guess I feel that the probability of 2 drives failing at the same time is very, very low. It's never happened to me "yet" in 18 or so years (knock on wood). But the chances of a RAID controller going down, or in this case the 323-NAS itself and maybe taking both drives with it (and/or/maybe just the data and mechanically the drive is still fine) are probably alot higher. So the chances of either or happening might cancel themselves out as all low probability

I think keeping 3 copies of data may be the way to go for me. 1 copy in the PC, 1 copy in a NAS backup on single drives (which is probably good enough for most people) and for the slightly paranoid a 3rd copy in a NAS or PC or whatever. That 3rd copy might be kept in another room, floor or offsite for the more paranoid types:)

[Jones Max]

gunrunnerjohn, what software do you use? all these years I've been doing backups it's always manually. It works the best I find

[gunrunnerjohn]

Well, I lied, I actually have another backup that I didn't mention.

I have a Synology DS209 as my primary NAS and backup.  It does a timed backup every other day to a pair of USB drives connected directly to the NAS.

For the other two NAS boxes, a DNS-323 and DNS-321, I use Beyond Compare www.scootersoftware.com and run it from task manager in the middle of the night when I'm not using the computer.  Task manager wakes the computer from sleep, runs the backup, and then puts the computer back to sleep.  I also use Cobian Backup http://www.educ.umu.se/~cobian/index.htm for local backups to my internal backup drive in preparation for all of the data to be copied to the NAS units.

There have been times I had to dip several levels into the backup, so I'm glad I have it.