On Thu, Oct 06, 2005 at 03:31:43PM -0400, AragonX wrote:
> So what if you have the same 18k file that is stored as you said, in 2 8k
> blocks and then one 2k chunk. Now you add more files to the system. Next
> you add another 18k to the first file the next day. Continue for a month.
> You would have something that looks like this right:
>
>
> 11111111 11111111 11222--- 22222222 22222222 3333333- ->
> -------- -------- -------- -------- -------- -------
> 1 - 18k
> 2 - 19k
> 3 - 7k
>
> I'm just guessing this is how the data would be written to disk. I don't
> really know. So on to day 2 when I add 18k to file 1, the data would be
> arranged on the drive platter as so?
>
> 11111111 11111111 11222--- 22222222 22222222 3333333- ->
> 11111111 11111111 11------
No, only the last chunk of any file is put into a split block, ie
11111111 11111111 --222--- 22222222 22222222 3333333- ->
11111111 11111111 1111----
> So I'm still getting fragmentation, just not nearly as bad as it is on a
> FAT or NTFS machine correct?
>
> I'm just trying to understand. I've heard the argument that "Linux does
> not have any fragmentation to worry about". I just don't see how that is
> possible on a desktop machine where lots of little files are modified
> frequently.
Linux *does* have fragmentation, just not generally enough to be a
problem. There are many other mechanisms going on (like dividing the disk
into cylinder groups) that operate to keep fragmentation manageable.
(Again with the proviso that I'm most familiar with UFS).
--
Little fly, thy summer's play my thoughtless hand
has terminated with extreme prejudice.
(with apologies to William Blake)
