Best swap cylinders?

[Mike Bilow]

John Twilley wrote in a message to Mike Bilow:

 JT> Hrm.  My ideal preference for swap would be in the middle.

 JT> /dev/hda1 45% of the drive 
 JT> /dev/hda2 10% of the drive <--- swap
 JT> /dev/hda3 45% of the drive

 JT> With the theory that the seek time would be minimized on
 JT> average iff the system spent time equally in each of the
 JT> other partitions. 

I recommend against this.  Assuming your machine is not so overcommitted that
it accesses the swap file as a second home, then it is more efficient to
allocate most of the drive as one large Second Extended partition with its
directory bands near the physical center of the drive.  Since the directory
bands are the most frequently accessed disk areas on nearly any Linux system,
and the physical center of the disk is the most rapidly accessed spot on
average, this usually works out well.

Also, since searches of the Second Extended filesystem are done using a binary
tree algorithm, which has efficiency which declines only logarithmically as
total partition size, you would force more physical disk access operations by
splitting your drive into small Second Extended partitions.
 
-- Mike