Below are the steps used to successfully access the data using 1 of the hard disks. The main internet links used to establish this procedure are How do I access data on a Netgear Stora formatted drive? and Desperate: mdadm fails to assemble raid saying devices are busy (use 'next by thread' to see all the email discussion)
This STORA appears to use a software RAID configuration and the data is formatted using the Linux XFS file system.
The basic idea is to have a desktop PC running linux, such as 64-bit Red Hat Enterprise Linux 6 (RHEL6) or CentOS6 which supports the XFS file system. Power it off, and attach the STORA hard disk as a secondary drive (it uses a SATA connection). Linux should recognize the hard drive (probably as /dev/sdb1) and using the steps below you can mount the drive. Then the data can be copied off the drive, or rsync'd to a remote machine.
# cat /proc/mdstat Personalities : [raid1] md127 : active (auto-read-only) raid1 sdb1 976562432 blocks [2/1] [U_] unused devices: <none>
The result shows what the active RAID1 device is, as seen above it is md127.
# mdadm --stop /dev/md127 mdadm: stopped /dev/md127
This stops the RAID device so you can act upon it. Look for confirmation that it is stopped.
# mdadm --assemble /dev/md127 --run /dev/sdb1 mdadm: /dev/md127 has been started with 1 drive (out of 2).
This starts the RAID with 1 drive
# mkdir /stora
This creates a local mount point for the STORA drive you are about to access
mount /dev/md127 /stora
The NAS hard disk is now accessible in /stora.
View the files and copy them to another location, rsync is a good tool for this.