Unmounting Disk Partition at Startup

You should be able to do this, the command you need is actually "Eject Disk" which works on both disks and volumes.

If you use Automator you can simply select the "Eject Disk" command and enter the name "Utility HD" in to the command then save it as an application.

If you put this in your startup items it should do the job.

If you put the volume name in you shouldn't need the get item action at all - try it and let me know.

Hi Allen,

I tried applescripts to disable a backup partition at startup but they were hard to set up for multiple users and were slow.

I have come up with something that does just what I want. It works at startup and affects all users. It is invisible and reversible, but it takes a some work to set up the first time. It assumes you are comfortable with unix. Be careful and use at you own risk, blah, blah, blah. This should not be tried by novices.

Create two text files. The first is named StartupParameters.plist and the second is unmountBackupDrives.

Copy and paste the text between the dashed lines in StartupParameters.plist:
-------------------------------------------------
{
Description = "unmountBackupDrives";
Provides = ("unmountBackupDrives");
}
-------------------------------------------------

Copy and paste the text between the dashed lines in unmountBackupDrives:
-------------------------------------------------
#!/bin/sh

. /etc/rc.common

StartService ()
{
echo "unmounting backup disks if present"

# repeat the following block for each drive/partition to unmount
drive=iMac\ backup
if [ -d "/Volumes/${drive}" ]
then hdiutil unmount "/Volumes/${drive}" -force
fi

drive=G5\ backup
if [ -d "/Volumes/${drive}" ]
then hdiutil unmount "/Volumes/${drive}" -force
fi
}

StopService ()
{
return 0;
}

RestartService ()
{
return 0;
}

RunService "$1"
-------------------------------------------------

In the above script you need to update the lines with "drive=" with names from your system. Note that the backslash is used to precede spaces in the drive name. If you only want to hide one drive or partition then you don't want the second block of code. You can add more blocks to hide other drives.

The rest of the work is done from the terminal:

Go to where the two text files are located and make the script executable:
chmod 755 unmountBackupDrives

Create a place to put your two files where they can be found by OS X:
sudo mkdir /Library/StartupItems/unmountBackupDrives

Move your two new files to this directory:
sudo mv StartupParameters.plist unmountBackupDrives /Library/StartupItems/unmountBackupDrives

When you shutdown and boot up next, your backup drives will be first automounted by the system and then unmounted by your new script. When you want them mounted, go to disk utility and you will see them greyed-out. You can manually mount them and they will be ready to go.

-Steve

Weird, I can do it here - you should be able to select the input fields in there...........I don't know what else to suggest if it won't do it, sorry.

Glad you got there in the end.