How does the external drive work with my Mac and how can it potentially solve my Pro Tools error message

just start protools and save your session to the external drive. that is all.

"Recording to the internal HD is not supported (or recommended). The read/write heads have difficulty accessing the audio files and OS at the same time."

HAHAHHAA

You need to ask someone who understands these things.

also, that seems like much more of an external drive than you need. I don't know...I record in protools on an old g5 to a $100 firewire external drive. we use a digi 002 though, not an mbox. i don't think it necesarily matters where in the chain you put the drive or the box, I believe macs are smart enough to sort those things.

You should buy an external firewire disk that has two firewire ports: FW was created to daisy-chain well, so you can connect the disk to yr Mbox. Some of the data will go back into yr computer, and depending on how you have things set up, some of it may pass directly to the disk. Regardless, FW is well-equipped to handle the situation. If you use a lappy, you may not realize how incredibly slow its internal disk is, and that this is likely the true bottleneck in yr setup (not the fact that "OS files" and audio files are accessed simultaneously: that issue is largely moot nowadays). Hence, yr external disk should NOT be bus-powered, but instead, externally-powered, full-size, SATA, and as fast as you can afford. The one you have picked out seems just fine except for that it has only one FW400 port, so if you do not have FW800 and only one FW400 port on yr computer, you may need to purchase a FW hub (about US$50).

Considering how clumsily I worded my question, thank you very much for all your replies, which have helped.

One thing - libcrypt, are you sure the Glyph GT-050Q doesn't have FW800? It seems to say in the "features" section that it does: "FireWire 400, FireWire 800, USB, eSATA interfaces". My IMac 24 does have a FW800 port but I have heard that FW800 doesn't work so well with LE Pro Tools, but I'm not sure if that's true.

I am really not with it today. I have just read your post again, and of course you were not saying that it doesn't have an FW800! Sorry!

The crucial question that you have been avoiding, TH, is this: What make and model of computer are you using? Is it a lappy?

Sorry -- My specs: iMac Intel 24" 2.16 GHz
10.4.11

I just found this on digidesign's website:
"FireWire 800 drives are not supported for record and playback with Mbox 2 Pro systems". Is anyone able to tell me whether this means I couldn't do the following: put a firewire from the FW400 port on the MBox Pro into the FW400 port on the External hard dribe, then a firewire from the FW800 on the Ex-drive to my iMac's FW800 port?

If I can't I may have to get a hub, although I am not even sure how a hub would work if the external drive only has one FW400 which is being used by the MBOX Pro.

I'm 99% sure you can't cross 800 with 400 like that. On the other hand, an external FW800 disk may "just work" with Pro Tools; the unsupported bit means you can't call up Digi and ask for support on yr setup.

I would avoid a hub if at all possible. It will slow things down needlessly. Just get a disk that you can return if it doesn't work out plugged into the FW800 port.

Somewhat more disturbing to me is the fact that the iMac internal 7200 SATA disk ain't cuttin' it. As far as I'm concerned, that should work for pretty much anything below the pro level. How many tracks do you record at once, generally speaking?

One of the great things about Logic is that it's free of most of the bullshit disclaimer-style Digi puts forth. One of the many great things, that is. Too bad Digi hardware blows the goat when used with non-Digi S/W.

Somewhat more disturbing to me is the fact that the iMac internal 7200 SATA disk ain't cuttin' it

yeah that is kind of weird. did you try reinstalling LE?

Modern HDDs far exceed the requirements for audio, unless you are doing lots of 24/96 tracks or something.

How much RAM do you have? Excessive paging could cause a problem.

If he's memory-starved, then he'll see an increase in page outs during a recording session.

TH, open Activity Monitor along with Pro Tools, select the "system memory" tab at the bottom, and keep an eye on page outs. If this number increases while you are using only Pro Tools, then you definitely have a memory problem.

"As far as I'm concerned, that should work for pretty much anything below the pro level. How many tracks do you record at once, generally speaking?" About three at a time, though I tend to bus sound effects (reverb etc) to one of the tracks. And the music I do involves a lot of stretching and pitch changing audio clips.

I have 447.39 GB available..

Hmm...It doesn't seem right does it... I maybe will have to try reinstalling LE.

I'll look at the Activity Monitor now.

Thanks libcrypt/everyone else.

Recording 3 tracks w/a few effects shouldn't stress the system at all.

Just using my plain ol' English skills here:

Audio device buffer underflowed.

to me sounds like the Mbox had difficulty filling the buffer with audio data, not that yr disk couldn't keep up. In other words, Digi is misdirecting you by blaming the matter on the disk. If it's not too late, I suggest that you send the Mbox back for replacement before it is too late.

OK, on rereading, it's not Digi, but "someone online". In other words, keep yr pocketbook closed for now.

Never trust "someone online", including me, if what they say doesn't make sense to you.

get a tascam 4 track

It is a bit too late to take it back, I fear - my guarantee was for one year. No problems till this enigmatic "buffer underflowed" message.

Yep, I think now I will try reinstalling before looking at an external disk.

By the way, the pages in and out started at 39400/0 then went up to 42174/0 when I started recording, and it stayed at this figure till I stopped recording after 5 minutes.

No pageouts means that you are A-OK for memory here.