Disk attempted to add is too small with an Identical disk??

Take a look at http://www.readynas.com/forum/viewtopic.php?p=206887#p206887

I think you don't need 3rd party software to delete partitions on Windows, but I'm not sure.

Have you used the disk in any other machine, in other words has it been formatted to any file system previously?

I had this problem with two identical 500GB Samsung HD501LJ disks and was never able to get my NV+ to take the second one. The only thing I came up with is that I had used the second disk for a temporary use and it had been formatted to NTSF (Vista). I wound up used a refurbished 750GB disk that Seagate had sent me as a replacement for a failed 500GB disk. The Samsungs even had sequential serial numbers (last four digits 1984 and 1985). Tried everything, even using Windows Disk Manager to delete all the partitions. The Samsungs were in bays 3 and 4 with two Seagate 500GB drives in bays 1 and 2.

Recently I used both 500GB disks in that very same NAS, but it was only the two and I started with a factory default.

You might try this - shut down the Pro and remove all the disks, noting which bay each one is in. Either tagging the drives or listing the serial numbers and the bay. Then insert the spare drive as a solo and do a factory default if the Pro doesn't do one on it's own. It won't take long to initialize a single drive. Then shut the Pro down, return all the other drives to their original bay and reboot. Then see if you can hot add the spare and have it accepted. I never tried this, as it didn't occur to me.

If it does not, it just means the drive is one sector short of the other drives. I am sure you don't want to hear the alternative - backup, factory default, restore. Three little words that on a Pro full of data will be a real chore. Of course we all know you maintain a current and complete backup anyway, don't we. So that step at least is already done.

Thanks PapaBear

Interesting suggestion. Will definately try this asap.
Quick question. When I do the factory reset with the one disk will the NAS then wipe all my users/shares for the other disks as well ??? :-(

thnx
And guess what....my fear for data loss is soooo big that I indeed backupped the whole thing last night, just in case

All of your settings and the OS (RAIDiator) are on the drives. So when you remove the entire set for your current array, when it sets up the single drive it will be all defaults. Then when you shut down the Pro and restore the original set of drives, all the settings and current version of RAIDiator will be there. Just make sure that the unit is OFF when you do this.

This was the only thing I could think of as it is entirely possible that when a drive is initialized on some other OS, such as NTSF, that even after the partitions are removed, there is some signature occupying a sector. I would be interested in the results.

The other thing to note is the hot-add (add while NAS is on) after putting the rest of your array back in the NAS. This should ensure the disk is wiped again and added into the array.

UPDATE: just took out the 5 disks, but it failed to recognise the one disk because it cannot mount the Raid it says.
Did a check with RAIDar and that gave me the message that the root is corrupt.
So I will indeed hook it up to a windows machine and remove all partitions if any

OMG. How stupid can one be.....???

It's almost too embarrasing to tell, but since you all tried to help, I will do :oops: :oops: :oops:
I thought I had put in the exact same disk, but it happens to be a 1000GB instead of a 1500.
I only found out when doing just a double double check.
Thanks for helping guys. Completely stupid mistake from my side.
Peter

Well on the plus side, you have a complete backup which is always a good thing. You now just have to wait for a replacement disk.

Just out of curiosity though, I am going to do some experiments on these two drives. They are spares and I want to see if there is a difference in the number of sectors.

Well, it turned out that before I could attempt an experiment on my NV+ which has a volume that is not important, I wound up experimenting with my primary NAS, my NVX BE. It has 2xHitachi 3TB drives and 2x1TB Seagate ST1000528AS drive (bays 3 & 4). The drive in bay 4 has been throwing SMART errors for a while and over night they increased form 278 to 334, where previously they increased by about 6 each time. I had a spare ST1000528AS sitting by, so I hot pulled drive 4 waited for the response from the system and then hot added the spare. It checked the drive and said it passed, but never started the resync, so I knew something was wrong. Checking the logs, the drive was "too small".

So, I shut the NVX down, removed the three good drives and then did a factory default on the "too small" drive. After it initialized and created the one drive volume, I shut the NVX down, removed that drive and put the three good drives from the array back in, and rebooted. After it booted, and was back on line (I was getting the message from the NVX that C: was unprotected) I then hot added the drive that it had said previously was too small. The NVX rejected the drive again as too small.

I pulled another ST1000528AS from the cabinet (I have a total of 10, 3 of which were spares), hot added it. It passed and the NVX started the resync process. Apparently, when a drive is "too small" even if the same brand and model (even in my one case of sequential serial numbers) there is truly something different about the drives. While it may take one of the Jedi who have been doing these tests for years to confirm, but my suspicion is that even if it is one sector smaller than the previous smallest drive, it will be rejected.

Yes one sector smaller is enough. You could connect the drive to your PC and see if anything can be done there.