dkm39@isy.liu.se (Rickard Westman) (03/22/90)
I am working on some programs which need to access disk devices directly for things like file system repair and file "undeletion". However, there are some things I would need to know, which I haven't seen documented anywhere. (Perhaps this is mentioned in some issue of AmigaMail, which is quite unknown in Europe.) 1. Where do I find the root block? Under FFS and OFS it seems to be located at the exact middle, rounded upwards if there is an even number of blocks. Can I rely on this? 2. Where are the bitmap pages located for large (>50 MB) partitions? In the root block there are pointers to 26 bitmap blocks, each representing 4064 physical blocks. This would limit the size of a partition to about 50 Mb, while I was under the impression that FFS supported disks of "infinite" size. So where do I find these extra bitmap blocks? I haven't been able to figure it out, since the size of my hard disk is less than 50 MB. I *do* want my programs to work on any disk device, so please enlighten me... --------------------------------------------------------------------------- Richard Westman, University of Linkoping, Sweden | riw@linus.ida.liu.se --------------------------------------------------------------------------- "Very few profound thoughts can be expressed in 80 characters."