paul@uunet.uu.net (Paul Martin) (08/21/89)
Can anyone out there in net land give some advice in calculating the geometry of a NEC D-2363 900MB disk running on the following combination of hardware and software : Rimfire 3200 controller, Sun 3/280S, OS 4.0.1 Our problem is that the NEC D-2363 disk is supposed to deliver a disk capacity of approx 900MB. We have a similar disk using a Sun Xylogics 7053 SMD controller on a second Sun server and this indeed does provide us with the correct disk capacity. The capacity difference stems from the fact that the recommended geometry of the *SAME* disk is substantially different for the two controllers, particularly in the number of heads. For the Xylogics controller, /etc/format.dat uses 27 heads, 964 cylinders and 67 sec/cyl giving a total disk capacity of 1743876 sectors or 851 MB of real data space. For the Rimfire rfutil suggests the use of 19 heads, 1022 cylinders and 67 sec/cyl giving a total disk capacity of 1301006 sectors or *ONLY* 635MB. I tried changing the geometry of the disk as seen by the Rimfire controller to make it match that of the Xylogics controller. I was able to format, label and newfs all the disk partitions without any problems. The UNIX commands newfs, df, mount, umount and dkinfo all worked - everything except for fsck which complained about a corrupt super block and instructed the use of the "-b" option to use an alternate super block. This made no difference every superblock seemed to be corrupted in the same way. However I was still able to mount/umount all the disk partitions ?? Perhaps some guru can explain that one ? Well I have now reverted back to the rfutil recommended geometry as this is the only labelling that I could find that would allow fsck to work. I really did not want to leave a system that would always hang on reboot - even if it meant losing more than 200 MB of disk space. Obviously there is something wrong with the geometry given in rfutil - and I would rather not experiment on our network master machine. Can anyone else throw some light on my confusion. Thanks in advance for any assistance, ================================================================================ Paul Martin European Computer-Industry Research Centre ECRC, Arabellastr. 17/II US: paul%ecrcvax.uucp@pyramid.pyramid.com 8000 Muenchen 81, West Germany ..!pyramid!ecrcvax!paul Tel. (089) 92699 124 Europe: paul@ecrcvax.uucp ..!unido!ecrcvax!paul ================================================================================