Hello
I don't know what a HDD "docker/toaster" is but I guess that it is somekind of device to which you attach your harddrive and then attach your HDD "docker/toaster" to your PC via USB 2.0 ..... (?)
You write : "I intend to use it as an external backup drive for backup purposes" but then ends up writing : "I want this new external 1TB Samsung HDD to be able to take the place of my internal primary HDD when the internal drive fails" also.
These two are in some ways contradictive :
First you express that you wish to use the the drive for "backup purposes" and then you expresses that you wish the drive to take the place of your present internal drive in case of drive failure.
A) If you wish for another drive to take the place of an already installed drive in case of total drive failure then install the secondary drive in your computer on the same controller and then use the manufactures drive manager/tool to copy the entire primary drive to the secondary drive , then take out the secondary drive and put it away for safe keeping - then if your present drive stops functioning you can mount the one you have in storage onto your PC as replacement.
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In theory you could partition your new secondary drive into more partitions and then use a drive tool to copy (and eventually shrink) the entire first partition from your primary drive onto the first partition on your new backup drive (which you in that case would have partitioned on that controller) by the means mentioned above (to the extend that the primary partition on your new drive had room for the data from the partition on your present primary drive) and then use the rest of the partitions on your new backup drive to backup other data to as you like.
but that is theory and theory only....
It is theory only because windows will most likely mess up things if you attach the secondary drive in that case/condition.
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B)
Primer : it's always a very good idea to partition and format the drive by the use of the controller on which you wish to use your drive.
If you wish to use your backup drive on a HDD "docker/toaster" then partition and format it using the HDD "docker/toaster".
With respect to backing up then you can use your HDD "docker/toaster" to put "images" of your present internal primary drives partition(s) by the use of tools such as "Norton Ghost 14.0" or "Norton Save & Restore 2.0".
http://www.symantec.com/norton/ghost
http://www.symantec.com/norton/save-restore
Such a "backup strategy" will allow you to place as many "drive images" as you wish, plus all other types of backups/"backup'ing", to your external drive. Plus restore from the external drive as you wish to another newly bought drive if your present internal primary drive fails to function.
C)
You might possibly be able to combine the two strategies by mounting your new backup drive on the same controller as your present internal primary drive and then partition your new secondary drive into more partitions (of which the first should be big enough to hold your present primary drives partition/partitions) and then leave the entire first partition (or the partitions you intend to have restored later) on your new backup drive empty and unformatted.
Then you could dismount your new backup drive and put it onto your HDD "docker/toaster" and then make a drive image of your present internal drive, by use of a tool as mentioned above but then only write the backup's and other data onto partitions you do not intend to use later to restore onto...
In that case if your present internal primary drive fails your should be able to mount your backup drive internally and then by the use of your tool (e.g. Norton Ghost 14) you could restore your drive images from from the partition where you have written it to onto the waiting empty partition(s) - but wouldn't that be a waste of space until then ?...
I advise you to go with option B) and then if your present internal primary drive fails then buy another drive and restore to that drive from your saved image from your external drive.
D)
With respect to "drive backups" a "new" solution has emerged with the Microsoft Windows Home Server software (O.S.) :
http://www.microsoft.com/windows/products/winfamily/windowshomeserver/default.mspx
This solution offers advantages over many others but it requires , apart from the software that costs around USD $100 (I think), a hardware platform on which to run the "Microsoft Windows Home Server".
However if you have more computers and/or wish to utilize other features that the "Microsoft Windows Home Server" offers (media streaming, Remote Access , Add-ins , etcetera ) then that is also a backup solution to consider.
With respect to examples of "Microsoft Windows Home Server" "Add-ins" please see here :
http://www.microsoft.com/windows/products/winfamily/windowshomeserver/add-ins.mspx
and here :
http://www.whsplus.com/
With respect to backing up Windows then while drive images are, as you seem to understand already, in many ways superior then in case your total hardware platform is lost then though you may be able to successfully restore onto another hardware platform then it is far from certain that Windows will run without problems if the hardware it is restored onto differs enough. Hence is always a good idea to make simple file backups of "personal content" now and then to optical storage such as CD or DVD or onto an external backup hard drive such as your HDD "docker/toaster".
It should be noted that for example Norton Ghost should be able to extract single files from images made but it is a lot easier just to get them from a simple "file backup".
And - oh by the way - no there ought to be no problem in using a partition of the size of 931 GB for use with a Windows PC, at least not if it is NTFS formatted , with respect to formatting and size though then bear in mind that some other devices such as NAS devices and multimedia devices (TV's ,DVD-recorders and such) is not always able to either read from NTFS or write to NTFS and partition size also may be an issue on other devices other than your PC.
I hope that all my writing has helped you to answer your questions and use your drives as you wish.
With Kind Regards
Thanks for taking the time and welcome to our forum!