I want to generate or extend a large file in an ext4 filesystem allocating space (i.e. not creating a sparse file) but not actually writing any data. I realise that this will result in the file containing the contents of whatever was there on the disk before, which is a possible security problem in some circumstances, but it isn't a problem here. Ideally what I'd like is a "make unsparse" bit of code. I'm happy for this to use the libraries, and work on an unmounted fs (indeed that is probably better). Supplementary question: can I assume that if a non-sparse file is on disk and never opened, and never unlinked, then the sectors used to to store that file's data will never change irrespective of other operations on the ext4 filesystem? IE nothing is shuffling where ext4 files are stored. -- Alex Bligh _______________________________________________ Ext3-users mailing list Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
