MacOS – mount an external NTFS drive as writable when running the install DVD

I stumbled on a post on IM.GETTING(THIS);, which explained the issue — and even provided a fix!

The problem seems to stem from the binary "fuse_wait" from NTFS-3G that's run as a final part of the mounting procedure - for some reason it can't detect that ntfs-3g mounted the volume and stays on a hopeless loop trying to detect this condition until it gives up after 15 seconds. So my workaround involves replacing the fuse_wait binary with a script that does more or less the same thing, but actually detecting (sort of) the mount operation and not timing out.

The fix

(Assuming the use of MacFUSE & NTFS-3G)

sudo mv /usr/local/bin/fuse_wait /usr/local/bin/fuse_wait.original
sudo touch /usr/local/bin/fuse_wait
sudo chmod 0755 /usr/local/bin/fuse_wait
sudo chown 0:0 /usr/local/bin/fuse_wait
sudo nano /usr/local/bin/fuse_wait

Copy & paste:

#!/bin/bash

MNTPOINT=$1
shift
TIMEOUT=$1
shift
MNTCMD=$1
shift

$MNTCMD "$@" &> /var/log/ntfsmnt.log
MNTCMD_RETVAL=$?

if [ $MNTCMD_RETVAL -eq 0 ]; then
        until [ `/sbin/mount | /usr/bin/grep -c "$MNTPOINT"` -ge 1 ] || [ $TIMEOUT -eq 0 ]
        do
                       sleep 1
                let TIMEOUT--
        done
fi

[ $TIMEOUT -eq 0 ] && RETVAL=1 || RETVAL=$MNTCMD_RETVAL

exit $RETVAL;

Save. Then:

sudo nano /System/Library/Filesystems/ntfs-3g.fs/ntfs-3g.util

Change the following line:

DEFAULT_NTFS_MOUNT_OPTIONS="auto_xattr"

to:

DEFAULT_NTFS_MOUNT_OPTIONS="auto_xattr,noatime,noappledouble,auto_cache"

Save. Reboot. Smile.

For details and alternative methods I wholeheartedly recommend reading through the aforementioned article and thank him, not me.

You hook into diskarbitrationd by using Apple's Disk Arbitration framework. Basically you call DASessionCreate() to create a DASessionRef, and then register one or more notification callbacks.

You would need to register for the DARegisterDiskMountApprovalCallback. This gives you a notification whenever diskarbitrationd is going to mount something new. By returning a DADissenterRef from this callback, you can prevent diskarbitrationd from actually mounting the file system.

Then you can mount the file system yourself and create shortcuts etc. using standard methods, such as the mount() system call.

Here's a direct link to the page in the programming guide, you'll need to examine:

https://developer.apple.com/library/mac/documentation/DriversKernelHardware/Conceptual/DiskArbitrationProgGuide/ArbitrationBasics/ArbitrationBasics.html#//apple_ref/doc/uid/TP40009310-CH2-SW1