While not wanting to get into a technical argument on this, I for one while
understanding the file system is better in linux than in windows, am sick and
tired of people saying there is no need and the lack of one in package managers,
if I for instance dl a huge dvd iso and it ends up with thousands of fragments
on say, a HD with lack of room to write it in one go, then it would be useful to
defragment it. I've had several occasions when writing a huge DVD iso was
problematic and by defragmenting it, i was able to write it properly. Also, it
would be nice to know all files can be placed up the front end of the drive to
reduce time between head read shifts.

What did you use to defrag it?????????????

I've never found one, but then again, i used Windows most the time so worries
about file system in Linux havn't been there until recently.

The Linux filesystems are designed to avoid fragmentation by leaving
lots of space after each file to allow for future growth.
Fragmentation is not a problem as long as the drive is not filled
beyond about 80%.

I'm so new to Ubuntu I have it on a laptop, it works well for me.

So far I haven't found anything about a defrag utility for the system. Can you
recommend one. Does Ubuntu happen to take care of this automatically? Is this
right in front of my face in the system pull down menu etc?

I've been using linux systems since 1994 and I've never defragged one.
Unix filesystems are naturally more resistant to fragmentation than pc
filesystems, and in any case, it's not an issue.

I've heard of various defrag projects over the years, which as far as I
can tell never found a niche, but recently I heard that there may be a
defrag utility for the ext4 filesystem, for those who really pine for
the old days of defragging their disks.

Here's a good explanation:

geekblog.oneandoneis2.org/.../why_doesn_t_linux_need_def\
ragmenting

You don't state what filesystem you're using (see the /etc/fstab
file). If you're using ext3 then, as I understand things, this is a
self-defragging filesystem (presumably, the same can be said for ext4
... don't know about ext2, though).

I was thinking the main benifit of a defrag tool on linux would be for
usb flash drives, which I presume would be susceptable to
fragmentation since they are usually FAT or FAT32, right?

You can just re-format them to ext. :) Any defrag tools there are ( and
there are only a few) are hard to use for newbies. They are commandline
tools that require a knowledge of device names and switches. Why put
yourself through the headache when you can avoid it? We use Linux for a
reason, so take advantage of its strengths. Besides, nothing stays long
enough on my FAT32 usb sticks to become fragmented and anything that is for
archival purposes are on a faster and more durable file system such as ext3
or 4.

Flash drives can be written to a (semi-random) limited number of times.
Defragging a flash drive would use up several of those writes.

I find I format any flash drive from time to time, which means I'm starting from
an unfragmented state.

The link you sent gives a good explanation of the Linux filesystem. You've
removed my concern about defragging my machine.