On Sun, Apr 10, 2005 at 03:26:12PM +0200, Norbert Preining wrote: > Hi all! > > I have a slight problem: I have an external disk which contains one big > filesystem (like a floppy) type ext3 (If you ask why: blame udev or > maxtor, or me because I am stupid) which is approx 60% filled. > > Now I want to have a partition table, ie a layout where the current > filesystem is the first partition, and the rest is as usual. > > Is this possible withotu destroying the data? Theoretically? Yes. Is it going to be easy? Unfortunatly, no one has written a tool to do this (as far as I know) and doing it manually is going to be extremely perlious. What this theoretical tool would do (I don't recommend trying to do this by hand!) is: 1) Shrink the filesystem just slightly using resize2fs so that there is room for the partition table. 2) Move the filesystem down to make room for the partition table. What is tricky about this: 1) It's an overlapping move, so you have to start at the back of the disk and work forwards. 2) You want some sort of program state checkpointing scheme so that if your system fails in the middle of the move, you don't end up with a completely toasted filesystem; it's critically important that the information about how far in the filesystem relocation you have been is recorded, so you can restart it after a system crash. 3) You need to know how far to move the filesystem, in order to make room for the partition table and start it at a suitable cylinder group boundary, so that partition table tools don't get confused/grumpy. 3) Create the partition table. Another approach that might work is might be: 1) Shrink the filesystem by 8 meg. 2) Copy the first 4 megabyte chunk to the end of the filesystem. 3) Add LVM2/device mapper partitioning information 4) Manually construct a new LVM2 logical partition which uses the new location of the first 4 meg chunk, and the location of the rest of the filesystem's 4 meg chunks. If you're not willing to do a lot of development and testing, the best way to do this is to buy or borrow a disk (disks are cheap!), and then create the partition table on the new disk, shrink the filesystem slightly using resize2fs, and then copy the partition over from the old disk to the new disk. - Ted _______________________________________________ Ext3-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ext3-users
