[Tsilou B.]

We have always used an external 120GB Firewire HD with our old iMac that doesn't support internal HDs larger than 128GB. The external HD is always connected and always on and is used just like a second internal drive. Since we installed Tiger on that iMac, we cannot use Fast user switching anymore. When another user logs in, Tiger unmounts the external disk and remounts it for the other user. Panther didn't do that. It's extremely annoying, because every running application that uses any files on the external drive crashes immediately when another user logs on.
Is there a way to stop this?

[ghporter]

I'll bet there's something going on involving permissions or ownership of the firewire drive. Have you tried repairing permissions? Which user owns the drive?

You might want to do something about how you store your files. Having application-required files on an external drive is not a reliable method of expanding your storage. I'd switch things around so that only user data was on the external drive, which might help the with issue.

[zeebe]

I am so glad that I am not the only one this happens to. We recently moved, and the firewire drive got dropped in its box about 2 feet and I thought that was the problem, as I don't remember it doing this before the move, but I guess I never switched users before the move. Anyone else have this happening to them??

[mportuesi]

The behavior you're seeing is intentional, and something Mac OS X has been doing since Panther. This is done so that people who use iPods and other removable media will automatically have their disks unmounted when they log off. Apparently it treats a user switch the same way. I don't think it's the right decision on Apple's part to do this, but there it is.

There's a system property list setting you can change to keep the disks mounted when you switch users. You'll have to go search the Mac sites to find it, or perhaps someone knows what it is and will post here.

[Tsilou B.]

Originally Posted by ghporter

I'll bet there's something going on involving permissions or ownership of the firewire drive. Have you tried repairing permissions? Which user owns the drive?

You might want to do something about how you store your files. Having application-required files on an external drive is not a reliable method of expanding your storage. I'd switch things around so that only user data was on the external drive, which might help the with issue.

Thanks for your help. Unfortunately, I couldn't find a way to keep the disks mounted. It doesn't matter which user owns them, and it doesn't matter if the "Ignore ownership on this volume" checkbox is checked. I have also repaired permissions but it didn't help. We do not store applications on the external drive but this problem still affects EyeTV (which stores its recordings on the external disk) or iDVD (when I switch users while it is saving a dvd image to the external disk).

Originally Posted by mportuesi

The behavior you're seeing is intentional, and something Mac OS X has been doing since Panther. This is done so that people who use iPods and other removable media will automatically have their disks unmounted when they log off. Apparently it treats a user switch the same way. I don't think it's the right decision on Apple's part to do this, but there it is.

There's a system property list setting you can change to keep the disks mounted when you switch users. You'll have to go search the Mac sites to find it, or perhaps someone knows what it is and will post here.

Panther did never do this. It treated the external drive just like a second internal one. Thanks a lot for the tip with the setting, I'll see if I can find anything about it.

[mportuesi]

Originally Posted by Tsilou B.

Panther did never do this. It treated the external drive just like a second internal one. Thanks a lot for the tip with the setting, I'll see if I can find anything about it.

I might be fuzzy on the details - Panther may have done it only on logout, not on user switch - but this is an issue I've had to deal with in the past, on an old iMac 400 running Panther. I had to re-apply the settings fix when I upgraded from the iMac to a Mac Mini.

On both machines, it was a problem for me since the machine(s) in question are running as media servers for my house, and the iTunes library is on an external Firewire drive. Logging out made the entire music library unavailable.

Sorry I don't know the setting off the top of my head.

[chris v]

I don't think this is default behavior. I have a FW drive mounted and on all the time home, and when switching accounts, it shows up in any/all of them, and is still there when switching back to mine.

[mportuesi]

I went out to find the original source for the property list setting I was mentioning, and I came across an apple discussion thread on the same topic as this thread. It may be a Tiger bug:

http://discussions.info.apple.com/[email protected]

[mportuesi]

Macintouch also has an article about this same issue as well:
http://www.macintouch.com/tiger17.html

Search for "Keith Bradnam"

[mportuesi]

Okay, this message has the system setting I was talking about earlier. It definitely does apply to Panther.

http://www.macosxhints.com/article.p...31103155828117

I'm not sure if this is your problem, or if you are suffering from a Tiger bug that Apple has yet to fix. But you could see if this helps.

[Tsilou B.]

Originally Posted by mportuesi

Okay, this message has the system setting I was talking about earlier. It definitely does apply to Panther.

http://www.macosxhints.com/article.p...31103155828117

I'm not sure if this is your problem, or if you are suffering from a Tiger bug that Apple has yet to fix. But you could see if this helps.

Hi mportuesi!

Thank you so much. I guess it's really because of the Tiger bug that I have had these problems, because I certainly didn't have to change this setting in Panther, but still: Our iMac works perfectly again.
It's really nice of you that you spent the time searching for the solution on the internet, even though you (currently) didn't have that problem yourself - just to help me.

[mportuesi]

Originally Posted by Tsilou B.

Hi mportuesi!

It's really nice of you that you spent the time searching for the solution on the internet, even though you (currently) didn't have that problem yourself - just to help me.

Glad I could help, and glad to hear your problem is fixed!

Regards,
Michael Portuesi

[neilw]

Furthermore, I just noticed this item from the listing of changes in 10.4.2:

External disks no longer unmount unexpectedly when switching users, if Fast User Switching is enabled.

Hopefully gone for good.