Thanks for the tip Tom. Apologies that must have seemed a basic query.
After battling with it for the most of day, I'm finally getting a successful boot with the SATA standalone and functioning SSH.
Two main issues were my Linux PC did not want to recognize the GoFlex SATA drive and my Linux distro did not have bsdtar so had to rebuild a load of packages to make it available. Perhaps there's an alternative, but I wanted to keep to the official instructions after my initial serious lapse in judgment

.
My Kernel output is listed below. Does this look good? Any signs that UBOOT is broken/needs updating?
Just to try to give something back to the great community here that has promptly helped me get back online, I've listed what I did to get things working. Hopefully it will help someone sitting with a door stop as I was a few days ago.
--Current Kernel Output for good boot. DHCP is valid and I can SSH--
$this->bbcode_second_pass_code('', '
sudo ubuntu@ubuntu:~$ sudo nc -lu 10.10.10.4 6666
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.17.4-1-ARCH (nobody@root-armv5-copy) (gcc version 4.9.2 (GCC) ) #1 PREEMPT Fri Nov 21 22:27:00 MST 2014
[ 0.000000] CPU: Feroceon 88FR131 [56251311] revision 1 (ARMv5TE), cr=0005397f
[ 0.000000] CPU: VIVT data cache, VIVT instruction cache
[ 0.000000] Machine: Seagate GoFlex Home
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 32512
[ 0.000000] Kernel command line: console=ttyS0,115200 mtdparts=orion_nand:1M(u-boot),6M(uImage),-(root) root=/dev/sda1 netconsole=@10.10.10.6/eth0,@10.10.10.4/
[ 0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[ 0.000000] allocated 262144 bytes of page_cgroup
[ 0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups
[ 0.000000] Memory: 121044K/131072K available (5567K kernel code, 347K rwdata, 1696K rodata, 259K init, 700K bss, 10028K reserved)
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
[ 0.000000] fixmap : 0xffc00000 - 0xffe00000 (2048 kB)
[ 0.000000] vmalloc : 0xc8800000 - 0xff000000 ( 872 MB)
[ 0.000000] lowmem : 0xc0000000 - 0xc8000000 ( 128 MB)
[ 0.000000] modules : 0xbf000000 - 0xc0000000 ( 16 MB)
[ 0.000000] .text : 0xc0008000 - 0xc071fff0 (7264 kB)
[ 0.000000] .init : 0xc0720000 - 0xc0760cec ( 260 kB)
[ 0.000000] .data : 0xc0762000 - 0xc07b8eec ( 348 kB)
[ 0.000000] .bss : 0xc07b8eec - 0xc0868264 ( 701 kB)
[ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[ 0.000000] Preemptible hierarchical RCU implementation.
[ 0.000000] NR_IRQS:114
[ 0.000009] sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 21474836475ns
[ 20.880674] Console: colour dummy device 80x30
[ 20.880693] Calibrating delay loop... 1191.11 BogoMIPS (lpj=5955584)
[ 20.970574] pid_max: default: 32768 minimum: 301
[ 20.970644] Security Framework initialized
[ 20.970693] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 20.970704] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 20.971273] Initializing cgroup subsys memory
[ 20.971303] Initializing cgroup subsys devices
[ 20.971318] Initializing cgroup subsys freezer
[ 20.971333] Initializing cgroup subsys net_cls
[ 20.971346] Initializing cgroup subsys blkio
[ 20.971359] Initializing cgroup subsys bfqio
[ 20.971373] Initializing cgroup subsys perf_event
[ 20.971386] Initializing cgroup subsys net_prio
[ 20.971442] CPU: Testing write buffer coherency: ok
[ 20.971773] Setting up static identity map for 0x54e0a0 - 0x54e0f8
[ 20.973104] devtmpfs: initialized
[ 20.975804] pinctrl core: initialized pinctrl subsystem
[ 20.976318] NET: Registered protocol family 16
[ 20.976712] DMA: preallocated 256 KiB pool for atomic coherent allocations
[ 20.977508] cpuidle: using governor ladder
[ 20.977525] cpuidle: using governor menu
[ 20.977616] Kirkwood: MV88F6281-A1, TCLK=200000000.
[ 20.977635] [Firmware Bug]: Feroceon L2: bootloader left the L2 cache on!
[ 20.977642] Feroceon L2: Cache support initialised.
[ 21.012170] vgaarb: loaded
[ 21.012506] SCSI subsystem initialized
[ 21.013035] usbcore: registered new interface driver usbfs
[ 21.013113] usbcore: registered new interface driver hub
[ 21.013229] usbcore: registered new device driver usb
[ 21.013389] pps_core: LinuxPPS API ver. 1 registered
[ 21.013398] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[ 21.013435] PTP clock support registered
[ 21.014424] Switched to clocksource orion_clocksource
[ 21.032935] FS-Cache: Loaded
[ 21.046148] NET: Registered protocol family 2
[ 21.047083] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[ 21.047110] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[ 21.047130] TCP: Hash tables configured (established 1024 bind 1024)
[ 21.047194] TCP: reno registered
[ 21.047207] UDP hash table entries: 256 (order: 0, 4096 bytes)
[ 21.047229] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[ 21.047433] NET: Registered protocol family 1
[ 21.049126] futex hash table entries: 256 (order: -1, 3072 bytes)
[ 21.061174] VFS: Disk quotas dquot_6.5.2
[ 21.061443] Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[ 21.063239] jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
[ 21.064593] fuse init (API version 7.23)
[ 21.066567] aufs 3.17-20141110
[ 21.066597] msgmni has been set to 236
[ 21.068399] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 250)
[ 21.068418] io scheduler noop registered
[ 21.068431] io scheduler deadline registered
[ 21.068721] io scheduler cfq registered
[ 21.069195] io scheduler bfq registered (default)
[ 21.069204] BFQ I/O-scheduler version: v7r6
[ 21.069410] mv_xor mv_xor.0: Marvell shared XOR driver
[ 21.104511] mv_xor mv_xor.0: Marvell XOR: ( xor cpy )
[ 21.144503] mv_xor mv_xor.0: Marvell XOR: ( xor cpy )
[ 21.144704] mv_xor mv_xor.1: Marvell shared XOR driver
[ 21.184500] mv_xor mv_xor.1: Marvell XOR: ( xor cpy )
[ 21.224500] mv_xor mv_xor.1: Marvell XOR: ( xor cpy )
[ 21.230029] Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled
[ 21.231109] console [ttyS0] disabled
[ 21.251209] serial8250.0: ttyS0 at MMIO 0xf1012000 (irq = 33, base_baud = 12500000) is a 16550A
[ 21.774125] console [ttyS0] enabled
[ 21.787077] brd: module loaded
[ 21.794794] loop: module loaded
[ 21.798341] sata_mv sata_mv.0: cannot get optional clkdev
[ 21.803830] sata_mv sata_mv.0: slots 32 ports 1
[ 21.810125] scsi host0: sata_mv
[ 21.813900] ata1: SATA max UDMA/133 irq 21
[ 21.819233] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0xda
[ 21.825758] nand: Micron MT29F2G08AAD
[ 21.829443] nand: 256MiB, SLC, page size: 2048, OOB size: 64
[ 21.835158] Scanning device for bad blocks
[ 21.920268] Bad eraseblock 760 at 0x000005f00000
[ 21.974479] Bad eraseblock 1226 at 0x000009940000
[ 22.066641] 3 cmdlinepart partitions found on MTD device orion_nand
[ 22.072938] Creating 3 MTD partitions on "orion_nand":
[ 22.078137] 0x000000000000-0x000000100000 : "u-boot"
[ 22.083612] 0x000000100000-0x000000700000 : "uImage"
[ 22.089070] 0x000000700000-0x000010000000 : "root"
[ 22.101534] libphy: orion_mdio_bus: probed
[ 22.105801] mv643xx_eth: MV-643xx 10/100/1000 ethernet driver version 1.4
[ 22.334454] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl F300)
[ 22.374484] ata1.00: ATA-8: ST1000DM000-9TS15E, CC92, max UDMA/133
[ 22.380698] ata1.00: 1953525168 sectors, multi 0: LBA48
[ 22.464487] ata1.00: configured for UDMA/133
[ 22.484761] scsi 0:0:0:0: Direct-Access ATA ST1000DM000-9TS1 CC92 PQ: 0 ANSI: 5
[ 22.505342] sd 0:0:0:0: [sda] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB)
[ 22.513459] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 22.519041] sd 0:0:0:0: [sda] Write Protect is off
[ 22.534782] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 22.560981] sda: sda1 sda2
[ 22.574935] sd 0:0:0:0: [sda] Attached SCSI disk
[ 23.256437] mv643xx_eth_port mv643xx_eth_port.0 eth0: port 0 with MAC address 02:50:43:1d:fc:a6
[ 23.265342] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 23.271899] ehci-pci: EHCI PCI platform driver
[ 23.276447] ehci-orion: EHCI orion driver
[ 23.280558] orion-ehci orion-ehci.0: EHCI Host Controller
[ 23.286025] orion-ehci orion-ehci.0: new USB bus registered, assigned bus number 1
[ 23.293947] orion-ehci orion-ehci.0: irq 19, io mem 0xf1050000
[ 23.314457] orion-ehci orion-ehci.0: USB 2.0 started, EHCI 1.00
[ 23.321315] hub 1-0:1.0: USB hub found
[ 23.325159] hub 1-0:1.0: 1 port detected
[ 23.329779] usbcore: registered new interface driver uas
[ 23.335294] usbcore: registered new interface driver usb-storage
[ 23.341377] usbcore: registered new interface driver ums-alauda
[ 23.347430] usbcore: registered new interface driver ums-cypress
[ 23.353514] usbcore: registered new interface driver ums-datafab
[ 23.359622] usbcore: registered new interface driver ums_eneub6250
[ 23.365897] usbcore: registered new interface driver ums-freecom
[ 23.371982] usbcore: registered new interface driver ums-isd200
[ 23.378001] usbcore: registered new interface driver ums-jumpshot
[ 23.384171] usbcore: registered new interface driver ums-karma
[ 23.390096] usbcore: registered new interface driver ums-onetouch
[ 23.396317] usbcore: registered new interface driver ums-realtek
[ 23.402399] usbcore: registered new interface driver ums-sddr09
[ 23.408418] usbcore: registered new interface driver ums-sddr55
[ 23.414414] usbcore: registered new interface driver ums-usbat
[ 23.420706] mousedev: PS/2 mouse device common for all mice
[ 23.427265] rtc-mv rtc-mv: rtc core: registered rtc-mv as rtc0
[ 23.433232] i2c /dev entries driver
[ 23.437395] sdhci: Secure Digital Host Controller Interface driver
[ 23.443599] sdhci: Copyright(c) Pierre Ossman
[ 23.448077] sdhci-pltfm: SDHCI platform and OF driver helper
[ 23.454465] ledtrig-cpu: registered to indicate activity on CPUs
[ 23.460638] usbcore: registered new interface driver r8712u
[ 23.466453] gre: GRE over IPv4 demultiplexor driver
[ 23.471388] TCP: cubic registered
[ 23.474759] NET: Registered protocol family 17
[ 23.479349] Key type dns_resolver registered
[ 23.484464] registered taskstats version 1
[ 23.489836] netpoll: netconsole: local port 6665
[ 23.494545] netpoll: netconsole: local IPv4 address 10.10.10.6
[ 23.500402] netpoll: netconsole: interface 'eth0'
[ 23.505157] netpoll: netconsole: remote port 6666
[ 23.509882] netpoll: netconsole: remote IPv4 address 10.10.10.4
[ 23.515862] netpoll: netconsole: remote ethernet address ff:ff:ff:ff:ff:ff
[ 23.522772] netpoll: netconsole: device eth0 not up yet, forcing it
[ 26.483684] mv643xx_eth_port mv643xx_eth_port.0 eth0: link up, 100 Mb/s, full duplex, flow control disabled
[ 26.496294] console [netcon0] enabled
[ 26.499988] netconsole: network logging started
[ 26.504701] rtc-mv rtc-mv: setting system clock to 2014-12-30 19:01:39 UTC (1419966099)
[ 26.514550] EXT4-fs (sda1): mounting ext3 file system using the ext4 subsystem
[ 26.544878] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)
[ 26.552647] VFS: Mounted root (ext3 filesystem) on device 8:1.
[ 26.578979] devtmpfs: mounted
[ 26.582841] Freeing unused kernel memory: 256K (c0720000 - c0760000)
[ 26.864215] random: systemd urandom read with 28 bits of entropy available
[ 26.876418] systemd[1]: systemd 217 running in system mode. (+PAM -AUDIT -SELINUX -IMA -APPARMOR +SMACK -SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID -ELFUTILS +KMOD +IDN )
[ 26.894997] systemd[1]: Detected architecture 'arm'.
[ 27.027436] NET: Registered protocol family 10
[ 27.033188] systemd[1]: Inserted module 'ipv6'
[ 27.039540] systemd[1]: Set hostname to <alarm>.
[ 27.530195] systemd[1]: Cannot add dependency job for unit display-manager.service, ignoring: Unit display-manager.service failed to load: No such file or directory.
[ 27.550081] systemd[1]: Starting Forward Password Requests to Wall Directory Watch.
[ 27.558345] systemd[1]: Started Forward Password Requests to Wall Directory Watch.
[ 27.566202] systemd[1]: Expecting device dev-ttyS0.device...
[ 27.594643] systemd[1]: Starting Remote File Systems.
[ 27.614581] systemd[1]: Reached target Remote File Systems.
[ 27.620438] systemd[1]: Starting Arbitrary Executable File Formats File System Automount Point.
[ 27.654593] systemd[1]: Set up automount Arbitrary Executable File Formats File System Automount Point.
[ 27.664259] systemd[1]: Starting Dispatch Password Requests to Console Directory Watch.
[ 27.672684] systemd[1]: Started Dispatch Password Requests to Console Directory Watch.
[ 27.680842] systemd[1]: Starting Paths.
[ 27.704571] systemd[1]: Reached target Paths.
[ 27.709104] systemd[1]: Starting Encrypted Volumes.
[ 27.734572] systemd[1]: Reached target Encrypted Volumes.
[ 27.740157] systemd[1]: Starting Swap.
[ 27.764571] systemd[1]: Reached target Swap.
[ 27.769015] systemd[1]: Starting Root Slice.
[ 27.824625] systemd[1]: Created slice Root Slice.
[ 27.829544] systemd[1]: Starting User and Session Slice.
[ 27.854605] systemd[1]: Created slice User and Session Slice.
[ 27.860560] systemd[1]: Starting Delayed Shutdown Socket.
[ 27.884593] systemd[1]: Listening on Delayed Shutdown Socket.
[ 27.890537] systemd[1]: Starting Device-mapper event daemon FIFOs.
[ 27.914586] systemd[1]: Listening on Device-mapper event daemon FIFOs.
[ 27.921300] systemd[1]: Starting /dev/initctl Compatibility Named Pipe.
[ 27.944588] systemd[1]: Listening on /dev/initctl Compatibility Named Pipe.
[ 27.951745] systemd[1]: Starting Journal Socket (/dev/log).
[ 27.974587] systemd[1]: Listening on Journal Socket (/dev/log).
[ 27.980701] systemd[1]: Starting LVM2 metadata daemon socket.
[ 28.004584] systemd[1]: Listening on LVM2 metadata daemon socket.
[ 28.010903] systemd[1]: Starting udev Kernel Socket.
[ 28.034584] systemd[1]: Listening on udev Kernel Socket.
[ 28.040110] systemd[1]: Starting udev Control Socket.
[ 28.064586] systemd[1]: Listening on udev Control Socket.
[ 28.070198] systemd[1]: Starting Journal Socket.
[ 28.094587] systemd[1]: Listening on Journal Socket.
[ 28.099824] systemd[1]: Starting System Slice.
[ 28.124604] systemd[1]: Created slice System Slice.
[ 28.129718] systemd[1]: Starting system-getty.slice.
[ 28.154603] systemd[1]: Created slice system-getty.slice.
[ 28.160206] systemd[1]: Starting system-serial\x2dgetty.slice.
[ 28.184603] systemd[1]: Created slice system-serial\x2dgetty.slice.
[ 28.191145] systemd[1]: Mounted Huge Pages File System.
[ 28.196989] systemd[1]: Mounting Debug File System...
[ 28.229185] systemd[1]: Started Set Up Additional Binary Formats.
[ 28.238944] systemd[1]: Mounting POSIX Message Queue File System...
[ 28.269461] systemd[1]: Starting udev Coldplug all Devices...
[ 28.295678] systemd[1]: Starting Create list of required static device nodes for the current kernel...
[ 28.329716] systemd[1]: Starting Setup Virtual Console...
[ 28.370572] systemd[1]: Started Load Kernel Modules.
[ 28.376352] systemd[1]: Mounted Configuration File System.
[ 28.382067] systemd[1]: Starting Apply Kernel Variables...
[ 28.412564] systemd[1]: Mounting FUSE Control File System...
[ 28.458241] systemd[1]: Starting Journal Service...
[ 28.483729] systemd[1]: Starting Slices.
[ 28.534984] systemd[1]: Reached target Slices.
[ 28.552930] systemd[1]: Mounting Temporary Directory...
[ 28.585756] systemd[1]: Starting Remount Root and Kernel File Systems...
[ 28.654677] systemd[1]: Mounted FUSE Control File System.
[ 28.684623] systemd[1]: Mounted POSIX Message Queue File System.
[ 28.704608] systemd[1]: Mounted Debug File System.
[ 28.724617] systemd[1]: Mounted Temporary Directory.
[ 28.764688] systemd[1]: Started Create list of required static device nodes for the current kernel.
[ 28.814655] systemd[1]: Started Setup Virtual Console.
[ 28.834720] systemd[1]: Started Apply Kernel Variables.
[ 28.859532] systemd[1]: Started Remount Root and Kernel File Systems.
[ 28.904644] systemd[1]: Started udev Coldplug all Devices.
[ 29.414673] systemd[1]: Started Journal Service.
[ 29.930933] systemd-journald[75]: Received request to flush runtime journal from PID 1
[ 33.800567] random: nonblocking pool is initialized
')
With help from Tom here and a few other forums here's what I did.
In my stupidity, when I was initially moving from stock I followed an outdated arch install guide, ran into problems with the SATA disk not dismounting and powered down the drive before I had setup the partitions/file system on the SATA drive properly.
Essentially the NAND (GoFlex base unit) was starting-up and then looking to the SATA drive to boot the filesystem. As the SATA drive was incorrectly configured the unit was stuck unable to load.
I had replaced the NAND configuration so could no-longer use the seagate USB reflash configuration to get me back to where I started.
To remedy this (as advised by Tom) I removed the SATA drive from the GoFlex enclosure and connected to my Linux PC (via SATA cable). For some reason my Linux PC would not detect the GoFlex SATA drive at all unless I used a Live CD. Once I booted from a live Linux CD (I used Ubuntu 11.04) with the GoFlex drive attached by SATA I was able to run through steps 9 to 12 of the official installation guide (
http://archlinuxarm.org/platforms/armv5 ... oflex-home).
Note: The guide isn't written for this setup, therefore you have to substitute any sda and sda1 entries for your own device ID. In my case sdb and sdb1 were my device and partition ID's. If you're using Ubuntu the Disk Utility application will list disks and their partitions to allow you to see the device ID's.
Another gotcha is that when completing step 10 and you exit with 'w' I regularly received a message stating that the partition changes could not be written as the drive was in use. Not sure where from but on the third attempt this went through successfully. This also happened less frequently using a Live CD to boot my PC.
After completing step 12 and ensuring the partition wasn't mounted, I removed the SATA disk and plugged back into the GoFlex. Setup the netclient listeners on my Linux PC as per:
$this->bbcode_second_pass_code('', 'sudo ifconfig eth0:0 10.10.10.5
sudo ifconfig eth0:1 10.10.10.4
sudo ifconfig eth0:2 10.10.10.2')
And then opened 3 terminal windows entering the following into each respectively - nc -lu 10.10.10.5 6666,nc -lu 10.10.10.4 6666,nc -lu 10.10.10.2 6666
The netclient listeners were just for me to watch/monitor the process and catch any errors. Not needed for a good boot.
And ended up with a solid green light on my GoFlex, could see it retrieved an IP from my router and could SSH into the IP using root:root.
Thanks again to the community, particularly Tom for your help on this.
TBP