site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Hi, No you cannot do that. Best regards, Anton -- Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer, http://www.linux-ntfs.org/ _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... On 8 Dec 2007, at 10:15, Damir Dezeljin wrote: The main question is WHY are you trying to do what you are trying to do? I'm working on a HSM (Hierarchical Storage Management) product. The lack of sparse file support seems a big show stopper for implementing such an application. I saw HFS and HFS Plus support resource forks - I'm wondering if the mentioned functionality can be used to display a different file size to the user than the 'real' size of the file on disk. Let suppose the file is truncated to zero length, but I still want to show the original size to the user. Is there any way (also not supported one) to do this? You cannot put an HSM application on top of an existing file system or at least not in a reliable way. For example what happens if people access the underlying file system without your HSM KEXT loaded? You need to design your own file system that incorporates HSM as one of its features... If you don't want to design a file system from scratch you can just take one of the existing ones and modify it so that it supports HSM and then copy its file system driver and modify that to support HSM. Then your product would be the new file system driver + management tools + a "newfs"/"mkfs" application to allow people to create such file systems. (Don't forget to rename the file system so it does not clash with the original one!) But note as things stand at present Mac OS X does not allow booting from a kext based file system so your users would not be able to have their boot file system be your file system. This email sent to site_archiver@lists.apple.com