Re: [gentoo-user] Anybody tried shake defragmenter?

[Alan McKinnon <alan.mckinnon@gmail.com>]

On Monday 03 August 2009 23:05:02 Paul Hartman wrote:
> On Mon, Aug 3, 2009 at 3:22 PM, Grant<emailgrant@gmail.com> wrote:
> > I know Linux systems aren't supposed to become fragmented, but I've
> > also read that it can happen eventually.  I'm on ext3.  I've read that
> > ext4 will have a defragmenter but that it doesn't have one yet.
>
> It's not that they aren't supposed to become fragmented, it is that
> they try to avoid it. There is a big difference, and things like
> streaming writes (downloads, bittorrents, etc) can cause extreme
> fragmentation.
>
> The time-honored way of fixing this is "backup, delete, restore". In
> my case my simple defragmenter is to move a file to tmpfs and then
> move it back to the hard drive. I always do this to files I'm about to
> burn to a CD/DVD to ensure the read speed is optimal.

Until one day someone write a super-duper disk cache algorithm that delays 
writes safely, notices that you are putting back unmodified something you just 
deleted, then reverts "to be deleted" flag on the block pointers. meaning that 
nothing has changed.

Lucky for us, I do not believe that such a driver has been written yet.
Unlucky for us, I believe that such a driver is entirely possible.

:-)

-- 
alan dot mckinnon at gmail dot com