On Sun, Feb 8, 2015 at 3:42 PM, Noel Chiappa wrote: > I don't know how the later systems work, but in V6, the swap device, and > the > start block / # of blocks are specified in the c.c configuration file (i.e. > they are compiled into the system). So you can take one partition, and by > specifying less than the full size to 'mkfs', you can use the end of the > partition for swap space (which is presumably what's happening with > /dev/rl0 > here). > ​Ah Noel - Thanks for the refresher course. That's right. I now remember it. I knew it was compiled into the kernel but I had forgotten the details. It was not until much later that the swap image became less screwed down/more reflexible. You first needed to get to larger disks (rp05/rp06) which had to be partitioned because they overflowed a 16 bit integer​. Once people started to partition them, then all sort of new things occurred and I that's when the idea of a dedicated swap partition came up. I've forgotten if that was a BSDism or UNIX/TS. Certainly by the time of Sam's 4.1A?? configuration tool that created conf.c and low.s it had already been in for a while. As I recall in V6 and I think V7, the process was first placed in the swap image before the exec (or at least space reserved for it). So you had to have a swap space to boot because to fork the "init" it needed to assigned to the swap space (chick/egg issue). When demand support was added to the kernel, the process did not have to have that requirement, so it meant swap set up could be a post initial program load operation for the start sequence. Clem Clem -------------- next part -------------- An HTML attachment was scrubbed... URL: