Using same iTunes library with external hard drive (EHD) on different PCs

Question

I know some of the issues related to this question have been touched on in different discussions but I don't think I have seen a clear yes/no and if yes, here's how, answer to my queries, so here goes.
Like another member, I would like to take my iTunes library with me when I'm away on holiday so that I can (for example) use an Apple TV with Home Sharing to watch movies in my library or pay albums in my music library while on holiday, in the same way as I am able to at home. I have a Samsung NC 10 notebook running Windows XP (which I would take with me with a Samsing Story EHD) and a Dell desktop. My iTunes media folders are now on the EHD and I think I have iTunes library files on the Dell and on the Samsung. Of course, if iTunes Match covered movies as well as music, I would use that and just take my Apple TV with me ... but it doesn't and seems not likely to.
By messing around and not properly understanding some of the discussions about this topic, I think my iTunes library looks as I expect it to be, on my Dell - though I have yet to test this by doing a synch with my iPad or iPod Touch. However, when I plug the EHD into the Samsung and open my library, I am missing at least one movie and I don't have any artwork showing for any of the movies. This is inspite of clicking Get Album Artwork, Consolidate Files and clicking to add, as a file (or folder) to the library, the missing movie which is on the EHD in the Movies folder of the iTunes Media.  In iTunes on the Samsung "Preferences>Advanced", the iTunes media location (on my EHD) is correct.
I have obviously messed something up trying to replicate my Dell desktop iTunes library on the Samsung. So:
can/should I start again (if that is the best thing to do) with getting my iTunes library properly on to my Samsung notebook? And, if yes, how do I do that?
is it really possible to have all that you need to run and use iTunes on an EHD (i.e. both media folders and the various iTunes library files (.itl, .itdb, .xml etc.)) so that whenever I plug the EHD into my Dell or Samsung I can access my iTunes library in the same way and via the same files? Or, do you always have to have the library files (at least) located on the PC you are connecting your EHD to (showing my ignorance here! )?
if you can have all the library files as well as media on the EHD (i.e. all of your iTunes library), I assume there is more to moving these from the C drive in my Dell to the EHD, than just cutting and pasting them into the EHD and then deleting similarly named files in C drive in the Samsung?
if all of my iTunes library can be located in the EHD, would I just access that (i.e. open my iTunes library) - whether on my Dell or the Samsung - by pressing the Shift key when clicking on iTunes as a programme on my Dell or Samsung, or - and I appreciate this is more basic computer knowledge than iTunes query - does the fact that I would need to access iTunes via some form of link on the relevant PC indicate why some iTunes library files would always have to reside on the PC rather than the EHD?
if the iTunes library files have to stay on the relevant PC, how can they be kept in synch - i.e. the more portable Samsung offering the same access and picture of my iTunes library as the Dell does - or is iTunes just not set up to do this, in which case I might as well ignore trying to replicate my iTunes library on the Samsung?.
Apologies for this long list of questions. Any pointers to where the answers lie or even better specific answers themselves would be very much appreciated.
Many thanks.

Answer 1

I think that's yes, yes, yes, yes, and not necessary...
Make a split library portable
Here are the typical layouts for the iTunes folders:
In the layout above right, with the media folder (everything in the red box) inside the library folder, the library is considered to be portable. A portable library can be moved from one path to another without breaking the links from the library to the media, and being self-contained it is much easier to backup and restore. (You do backup, don't you?).
You can rearrange things to make a split library portable by taking a number of small steps which don't break the library.
Before you start any media files that are outside of the media folder will need to be consolidated. If the library is in the old style layout then it should be upgraded to iTunes Media Organization (Library > Organize Library > Rearrange files in the folder <Media Folder>) to ensure that iPod Games, Mobile Applications etc. are brought inside the media folder, otherwise the links to these won't survive changes in the path of the library.
The basic non-fatal manipulations are:
You can create or connect to an alternate set of library files by holding down Shift (Win) or Option (Mac) when starting iTunes. (Note iTunes will continue to use this library until you use the same method again.)
You can move the library files to a new location and connect to it there as long as the media stays put.
You can move the library files and the media together if the media folder is a direct subfolder of the library folder.
If you have already moved/copied the media content from a subfolder of the library folder to a different location then you only need to copy the library files for it to appear as if you have moved the entire library in the way allowed above. I.e. just copy the library files into the parent folder of the media folder.
You can rename the media folder to iTunes Media (if it isn't already) if the media folder is inside the library folder.
iTunes uses the name of the folder holding the library files as the window title. Having made a library "portable" you may need to take a final step of renaming the library folder to iTunes or, if the library files have ended up at the root of a drive, moving all of the library files and content folders into a new folder called iTunes.
IMPORTANT: After each change you need to open, test and close the relevant library before attempting another change. If a change broke the library, undo it or revert to using the previous set of library files.
In essence all you need to do to join up a split library and make it portable is copy the library files into the parent folder of the media folder on the external/secondary drive and use the hold-down-shift/option-when-starting-iTunes method to connect to it. Other manipulations may be required to normalize the library so that the library and media folders have standard names.
tt2