Re: 10.4.7 Has Swap Memory Usage Gone Up With the Advent of 10.4 for you?

In article <tomstiller-8B60B6.17023805092006@xxxxxxxxxxxxxxxxxxxxxxxx>,
Tom Stiller <tomstiller@xxxxxxxxxxx> wrote:

In article <haberg-0509062154380001@xxxxxxxxxxxxx>,
haberg@xxxxxxxxxx (Hans Aberg) wrote:

In article <tomstiller-4CB560.15344605092006@xxxxxxxxxxxxxxxxxxxxxxxx>,
Tom Stiller <tomstiller@xxxxxxxxxxx> wrote:

Default allocation block size for HFS+ on Mac OS X is 4KB (8 sectors).

How do you check this?

The easiest way is to create a 1 byte file and check its size with Get
Info.

OK. I just created a file (via pico) with just the single character "1"
in it.

Finder in Column View says "4KB on disk (2 bytes)", as does Get Info.

ls -l shows 2 bytes.

hexdump shows that a line feed terminator has been added to the single
byte, hence the 2 bytes rather than 1.


And what is the difference between bolcks and sectors - I thought
they were the same.

Normally they are, but an allocation block is not the same thing as a
disk block or sector. It is the unit of disk assigned (in multiples, if
necessary) to files as they grow.

Mine is a UFS volume. In addition, I have a vague memory of that some
file systems (UNIX?) may have more than one file in a sector. So
there might be a difference between "block size" and "granularity".

I don't know. but I doubt that the filesystem permits more than 1 file
per block.

Back to an earlier poster's mention of cluster size. In this context a
cluster is, say, 8 blocks (4KB). Somewhere in the file system is a
bitmap which tracks used and free clusters. To avoid an overly huge
bitmap (i.e. 1 block per cluster), the file system provides a larger
number as a default.

--
Paul Sture
.