Joe's Random Ramblings

I've had a NAS (Network Attached Storage) box for years. I've been using a 1-TB RAID 1 setup for it. That 1 TB got used up. 99% full.
Since the manufacturer, D-Link, doesn't sell this particular model anymore, they haven't updated the firmware in years. Their firmware limits the disk size to 2 TB.
I thought I'd have to buy a new NAS device to be future-safe for bigger storage media.
But, I recently became aware of an Open Source firmware for these D-Link NAS boxes, called Alt-F. Alt-F supports disks up to 4 TB.
I installed ALt-F on my D-Link NAS last weekend. It worked without problems right out of the box.
So, on Monday, I ordered 2 4-TB SATA drives to put in the NAS. They arrived today. Put them into the box, selecting RAID1, and off we go.
I am right now transferring data from my 1 TB drive to the new 4 TB disk array, having connected one of the 1 TB disks to my Linux box.
I initially had some minor issues with mounting the old drive, because it's one disk out of a Linux Software RAID.
As it turns out, Linux detects the drive as a RAID drive, and creates a /dev/mdx entry, but doesn't really tell you about it. And it doesn't let you mount it, either, because it's only one disk from the RAID.
The technical desciption:
After googling a bit, I found that a 'cat /proc/mdstat' shows you if Linux detected the drive. If I close the /dev/md127 device that Linux gave me on bootup, with mdadm -S /dev/md127, I can then use mdadm --assemble --force on the device, and then I can mount it normally as an ext3 partition. That was all I needed to be able to copy files from the old drive to the new drives in the NAS. Even with a GBit network connection, it takes a while to transfer 1 TB...
This is what df reports right now:

Filesystem                    Type            1M-blocks    Used Available Use% Mounted on
/dev/md0                      ext3              936374M 918270M    18104M  99% /mnt/hd
192.168.2.110:/mnt/md0/       nfs              3754944M  57527M  3697401M   2% /mnt/nas