Adding multiple external HDD's

[Freeman3030]

Hi, I've got the basic 21.5" iMac with the 500GB HDD. I've only got 50GB free so was going to turn my old laptops HDD into an external HDD by putting it in an enclosure. No doubt that it will get full before long as it's only 250GB in size. (I take lots of photos and videos) so I have 2 questions.

1) When my iMacs internal HDD gets full, will the other files I add just spill into the next available HDD? e.g. importing photos into aperture, will it refuse to do it or like I say, spill into the external drive?

2) I was thinking about getting a 3rd external HDD of quite a large capacity (probably 2 or 3TB) and using time machine to back up all of the external drives I add on as and when I need them. Is it possible to backup data onto one drive that is stored on multiple drives?

 

[SandboxGeneral]

Hi, I've got the basic 21.5" iMac with the 500GB HDD. I've only got 50GB free so was going to turn my old laptops HDD into an external HDD by putting it in an enclosure. No doubt that it will get full before long as it's only 250GB in size. (I take lots of photos and videos) so I have 2 questions.

1) When my iMacs internal HDD gets full, will the other files I add just spill into the next available HDD? e.g. importing photos into aperture, will it refuse to do it or like I say, spill into the external drive?

2) I was thinking about getting a 3rd external HDD of quite a large capacity (probably 2 or 3TB) and using time machine to back up all of the external drives I add on as and when I need them. Is it possible to backup data onto one drive that is stored on multiple drives?

#1 No it will not automatically spill data over from full HDD to another one. You have to manually tell each application where to save it's files.

#2 Yes I believe so. You just need to set it up in the Time Machine options. (I'm at work on my Windows machine, so I cannot check to see if this is true right now).

EDIT: A quick Google search turned up this answer:

I have a question for anyone who has upgraded to Leopard, is using Time Machine, and has more than one external drive attached. Does Time Machine backup your other external drives, or just your internal drive?

Example: Let’s say you have an iMac with an external drive (A) attached containing all of your active files. You then attach another drive (B) to use as your Time Machine backup drive. Is Time Machine pulling files from Drive A?

I can’t seem to find the answer to this anywhere. One of the guys at the Apple store thought that TM only pulled from your internal drive, but he wasn’t sure. If this is true, than Time Machine just became totally unusable for me. All of my files are located on externals, including my iTunes and iPhoto libraries.

If anyone can shed some light on this it would be greatly appreciated.

UPDATE: Thanks to the comments by bernd and Dave, it looks like the answer is yes… Time Machine will pull from other external drives. I’m glad the Apple store guy was wrong.

UPDATE #2: According to this comment over at The Apple Blog, non Time Machine external drives are automatically put into the exclude list. If you want your external to be backed up, you need to open Time Machine and remove it from the list.

 

[spidey3]

#1 No it will not automatically spill data over from full HDD to another one. You have to manually tell each application where to save it's files.

Actually, Lion provides CoreStorage - which allows one to span a logical volume across multiple actual partitions, each of which can be on different physical disks. Limitation is that, looking at the documentation, I don't yet see a way to dynamically grow a logical volume by adding more physical volumes to the logical volume group.

See man diskutil for details on this.

Spidey!!!