Re: lots and lots of disks again

Andries Brouwer
2004-02-10T20:10:16Z

Kurt Garloff writes:

+/* Major / minor to disk mapping, from Matthew Wilcox, corrected
+ * (mail to linux-scsi@vger.kernel.org from 2003-10-16)
+ *
+ * major p2 disc2 disc p1
+ * |............|..|..........|....|....| <- dev_t
+ * 31 20 17 8 7 4 3 0
+ *
+ * We allow 64 partitions per disk, by adding two more bits.
+ * Inside a major, we have 16k disks, however mapped non-
+ * contiguously. The first 16 disks are for major0, the next
+ * ones with major1, ... Disk 256 is for major0 again, disk 272
+ * for major1, ...
+ * We can't currently use the partitions beyond 16, as the
+ * genhd infrastructure expects contiguous minors.
+ */

It is true that the first step needed is some agreement on
how to assign device numbers to disks and their partitions.

The above suggestion is really ugly, however.
I can hardly imagine that we would like to start such crap
while still in the design phase.

Andries