24 Apr
2018
24 Apr
'18
2:24 a.m.
It also makes no sense because disks of the day were constant angular density (unlike CDs
for example, which are constant linear). There’s no different in transfer rate anywhere
on the disk. Each track has the same number of sectors.
We spent a lot of time in those days with “elevator” algorithms and clustering inodes to
try to minimize seek time. The other thing that was done on the fancier devices (not
often found on PDP-11s) was optimizing where you were in the rotational angle.
The original UNIX filesystems were dumb. It was <boot
block><superblock><inodes><datablocks>. Wasn’t until later things
like the Berkeley file systems that things started to get more clever in layout.