roeder@sbsvax.UUCP (Edgar Roeder) (02/21/89)
Last weekend i tried to address my SH205 as one Filesystem via /dev/hd5 under Minix. I ran across one serious problem. At boot time the physical sector 0 of the harddisk is used to determine the size of the harddisk and the available partitions. When you address it as a single filesystem via minor number 5 the same sector 0 is now used to hold data. The next time you try to mount this drive after a reboot the system refuses this because the partioning info is not valid anymore. My proposed solution is to use minor 5 to address the whole disk without sector 0. You have still access to this sector via minor 0. A patch to stwini.c follows. - Edgar ----------------------------- start of patch ----------------------------------- *** stwini.c.old Mon Feb 20 18:43:31 1989 --- stwini.c Mon Feb 20 18:43:17 1989 *************** *** 105,111 **** if (pi[minor].pi_flag == PI_INVALID) pi[minor].pi_size = 0; } ! pi[minor].pi_size = hi.hd_size; } TRACE( for (r = 0; r < MAX_MINOR; r++) --- 105,113 ---- if (pi[minor].pi_flag == PI_INVALID) pi[minor].pi_size = 0; } ! /* physical sector 0 is needed for partition info */ ! pi[minor].pi_start = 1; ! pi[minor].pi_size = hi.hd_size - SECTOR_SIZE; } TRACE( for (r = 0; r < MAX_MINOR; r++) ------------------------------ end of patch ------------------------------------
hcj@lzaz.ATT.COM (HC Johnson) (02/23/89)
In article <689@sbsvax.UUCP>, roeder@sbsvax.UUCP (Edgar Roeder) writes: > Last weekend i tried to address my SH205 as one Filesystem via /dev/hd5 under > Minix. When you address it as a single filesystem via minor number 5 the > same sector 0 is now used to hold data. > My proposed solution is to use minor 5 to address the whole disk without sector There are many ways to change stwini.c but please, not this way. /dev/hd5 is the WHOLE disk, and is, in the UNIX(r) spirit, there to allow backup of the whole thing. If you want to add a new partitioning scheme use hd6 and hd7 which are not implemented. I prefer hd6, as it never will be implemented on the ATARI, as it does bad blocks differently. Howard C. Johnson ATT Bell Labs att!lzaz!hcj hcj@lzaz.att.com
johan@nlgvax.UUCP (Johan Stevenson) (02/24/89)
In article <689@sbsvax.UUCP> roeder@sbsvax.UUCP (Edgar Roeder) writes: >My proposed solution is to use minor 5 to address the whole disk without sector >0. You have still access to this sector via minor 0. I do not agree. Minor 5 is supposed to access the whole disk. You can already do what you want to do by allocating the whole disk minus sector 0 as the first and only partition. -- Johan W. Stevenson johan@pcg.philips.nl Philips Research