Hi Scottman, I am trying to understand this better - would you say that the main purpose of a scratch file is to create a "virtual space" on a FAT or NTFS drive (which cannot normally retain Linux permissions) within which the permissions (and symlinks?) CAN be maintained correctly?
Are there other benefits you have found?
cheers!
Scratch File Tool
Yeah, that's right. What he called a scratch file is simply a file which is mounted via the kernels loopback device -created explicitly with 'losetup' or with 'mount -t loop). This works with any file system. The file (formatted with a filesystem) resides on the 'host' filesystem as a a single item -the direntry function doesn't know anything about the content.
This all work fine on NTFS -even without ntfs-3g. The native read-write mode of the kernels ntfs driver could even handle this. The difficult thing is getting the file created on the NTFS in a sane way -which means that it will pass checkdisk. Of course, creating the file under windows would be best -but not really what we want. The kernel-native RW ntfs driver will not work nicely for this, ntfs-3g would be better for creating the new file on NTFS -and for mounting the device for later access to and mounting of the file with the loopback device. The file can be formatted to whatever you like.
This all work fine on NTFS -even without ntfs-3g. The native read-write mode of the kernels ntfs driver could even handle this. The difficult thing is getting the file created on the NTFS in a sane way -which means that it will pass checkdisk. Of course, creating the file under windows would be best -but not really what we want. The kernel-native RW ntfs driver will not work nicely for this, ntfs-3g would be better for creating the new file on NTFS -and for mounting the device for later access to and mounting of the file with the loopback device. The file can be formatted to whatever you like.