What do you do when external hard drive runs out of space?

External drives can be daisy-chained. You can have more than one external drive in use at the same time.

Of course you could get a second, identical external drive and put them into a striped RAID. Or you could purchase an enclosure that can handle 2 TB drives and install drives in a striped RAID configuration. A four drive enclosure that can handle up to 3 TB drives could provide as much as 12 GBs of online storage in a RAID configuration.

Since you can daisychain FW drives, you could plug in more than one drive and put your iTunes library on one and your pics (or whatever else) on another. That way you'd have access to both. As far as I know, there is no way to put half of your iTunes library on one drive and the other half on another. That's about the only way I can think of to handle it, but maybe someone else will have a better idea.

As far as I know, there is no way to put half of your iTunes library on one drive and the other half on another.

As a technical observation you can, if you manage your own media. My library was on 2 drives for a long time. You might even be able to do it now if you change media location preferences but do not let iTunes update old files to the new location, just start saving new ones there. This is more of an academic observation rather than something I would recommend doing because it makes it messy when trying to move the collection at some future date.

Limnos is right.

If you go to your itunes library preferances.

select advanced and you will see a screen like below.

you can uncheck the copy files to itunes media folder when adding to library. Also uncheck the Keep itunes media folder organized.

This will allow you to manually add the files. From another drive and not have them copy to your full drive. Also if you have the hard drives and or if you have a extra drive you can store your files on you can create a raid of both drives to make one large drive. Just make sure you keep both drives plugged in at all times.

IE if you have 2 250 gig drives you can create a 500 gig drive.

Check this video on youtube out about how to create a raid 0 set.

Also Big Joon. If you have 2 or 3 external firewire drives you can daisey change them by plugging one into the other. it does not matter the order. They will all mount on your computer. You may be interested in watching the raid 0 set video as well.

JUST REMEMBER IF YOU MAKE A RAID IT WILL DESTROY ALL THE DATA ON THE OLD DRIVE. ONLY DO THIS IF YOU HAVE THAT DATA BACKED UP ! OR IF THE DRIVES WERE EMPTY IN THE 1ST PLACE !

If I have 2 to 3 external hard drives daisy chained, only 1 external hard drive would show up on my desktop? Therefore, I can continue having my Lightroom and iTunes access media from only 1 external hard drive?

No, each external drive will show up on your desktop. If you have 3 drives attached with one partition each, you will have 3 icons showing on the desktop. They may be hooked up together, but they remain separate entities.

As for the libraries, you've gotten some more detailed answers.

I would consider a drive from OWC:

http://eshop.macsales.com/shop/firewire/

I've got the Mercury Elite Pro - great drive and very quiet.

WD makes good drives, but their enclosures aren't so much. Besides, their software does more harm than good it seems and most of them are not bootable (if you want to have a bootable clone at some point). FWIW: you do not need any software included on any external drive (unless you want it).

By the way, I have two of the LaCie's and they're fine.

I would add to this the fact that Lightroom doesn't care where your pictures or video are. They can be scattered around a variety of drives and you can choose wherever you want your lightroom database to exist. It may grow fairly large but nothing that's a big concern if you have terabytes of storage.

Many people such as myself run Lightroom from an SSD based iMac. I have more songs and pics and video than could possibly be stored on my little 256GB boot SSD so I have four Western Digital Caviar Black 2TB drives housed in two OWC Mercury Elite Pro (I think that's the model) drives. Take care to be sure you are getting hard drive cases that support JBOD (just a bunch of disks) if you want to see your internal drives separately. Many enclosures assume you want to combine two internal drives in a RAID configuration for speed.

http://eshop.macsales.com/item/OWC/MEPQ946QL2K/

That enclosure will allow you to install (very easy) two sata drives of your choice and use them independantly.

This is the drive I recommend. http://www.newegg.com/Product/Product.aspx?Item=N82E16822236501 Fast, reliable and full speed (no "green" technology to reduce it's speed).