Page 137 - slides.dvi

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Unix
1.
4.
3.
2.
The
Case
On
On
Can
If
Basic
read
Study—
Answer:
not,
Check
write
Locate
Return
cache
Question:
I/O
if
idea:
“Typically”
Buffer
do:
do
call
in
read
data
keep
when
Subsystem
relevant
same
sync
from
buffer
from
prevents
metadata
Cache
copy
does
first
disk
of
too
every
blocks
85%
buffer
cache.
data
—
30
of
into
three,
some
(from
cache.
and
actually
parts
implied
seconds
memory.
inode)
problems?
of
then
hit
to
disk
disk
flush
disk?
in
update
dirty
transfers.
version
memory
in
buffers
for
to
cache,
speed.
disk.
not
on
disk.
133