Andy wrote:
On Tuesday, June 2, 2020 at 2:54:00 PM UTC-5, Paul wrote:
KenK wrote:
Anyone have any idea what the computer is doing so actively when you aren't
using it? I often see the activity light flickering but have no idea what
it's doing. Sometimes no light activity.

TIA
That's the defragmenter running, and moving around prefetch
files or something. If you move the mouse, or attempt to investigate,
the defragmenter will frequently exit so you can't see what it's doing.
It doesn't exit immediately - that activity light can stay illuminated
for 30 seconds or so, after you try to get into the OS.

You might watch it with ProcMon (Process Monitor, Sysinternals), if
you want to see what it's doing. At the time, that's what I used
to verify what sector addresses it was using.

The prefetch movement thing can get into a loop. I could hear
a slight "singing" noise coming from my previous hard drive,
and the defragmenter doing the file moves, was moving the
same sectors to the same place, a "local minima" in the algorithm.
Just moving some files around a bit, affects the maths enough
that it stops pounding on that item. The program did not realize
that reading from sector 1234 and writing the stuff back to
sector 1234, was pointless. And done at high speed, it makes
the drive "sing". Moving a few files around, is sufficient
to have it read from 1234 and write to 5678, and that breaks
the loop and eventually it will stop when it's "satisfied".

The company who wrote the WinXP defragmenter is "President Software"
or such. There might be some Wiki info on it. The defragmenter was
not written by Microsoft. Whereas I suspect Microsoft wrote the
defragmenter on the Vista+ ones, as the defragmenter is much more
practical and not a "showoff". The Vista+ versions focus on "performance"
and are not a beauty contest like a commercial defragmenter is.
That's why the Microsoft defragmenter finishes before a commercial
one would. No shoeshine. But back in the WinXP era, Microsoft
contracted that part out, so the result has commercial quality
behavior, including a prefetch shoeshine without you knowing
what is running. And that makes the LED come on.

Paul

I am surprised Windows does not use a better file system like ext3 or ext4.

Neither require defragmenting.

Andy

This particular activity I'm referring to, is the pre-positioning of
files. Rather than defragmentation. The .pf files are used somehow,
to keep track of what needs doing.

The defragmenter is rather useless, because it does not defragment
white space, and there is a tendency for a freshly defragmented
volume, to fragment again.

Consequently, you "don't do it that way".

I remember one time, trying out the built-in defragmenter, and
it was still running the next morning (eight hours later). I said
to myself "I can do better than this", and I came up with a method
which could prepare a file system, in about half an hour, no matter
what state it was in. And that didn't use a defragmenter. It used
Robocopy instead.

Now, if we fast forward a bit, and look at Windows 10, for the
most part, that does not need user attention. It uses a lightweight
defragmenter, which can be scheduled by the OS, so that you hardly
ever see it. It leaves gaps between files. It doesn't pack
the files shoulder to shoulder. It does *not* defragment any
file larger than 50MB or so (those don't need to be defragmented).

If you were using a Windows 10 machine today, the topic would hardly
come up.

There are ways you can chew the **** out of a file system, in
Windows 10, but you have to put your mind to it. Just the
other day, I managed to make a 17% fragmented volume, and rather
than defragmenting it the long way, I just repaved the volume
using Macrium. Macrium will do some amount of defrag, during
a Restore operation, if you modify the partition size a tiny bit.
The Restoration mode changes to a kind of file by file operation,
and the image restored has close to zero fragmentation.
The result is not guaranteed in any way, and no documentation
refers to this behavior.

That's one reason you don't keep your movie collection on C:
with the OS. By separating your data collection from the OS,
it allows the occasional backup or cleanup to take place,
without involving gobs of unrelated data. You can do a backup
in less than ten minutes, do a restore in less than ten minutes.

EXT4 is good on hard drives. But, it represents extra wear on
flash based storage, due to the additional journal writes.
You can see this when Macrium backs up an EXT4 partition, and
the backup file is larger than the file set - the extra space is
overhead in the file system. I use nothing but EXT4 for Linux
on hard drives, because rotating disks don't care about stuff like that.

Most of the SSDs here, are for Windows, where the extra speed
is needed to make up for the bad hygiene (Windows Defender scanning,
indexing and so on). WinXP is still on hard drives. Linux is on
hard drives.

Paul