Re: Minimising defrag for partition copying by XP

Previously zappo <zappo@xxxxxxxxx> wrote:
zappo <zappo@xxxxxxxxx> wrote:
Arno Wagner <me@xxxxxxxxxxx> wrote:
Previously zappo <zappo@xxxxxxxxx> wrote:
Arno Wagner <me@xxxxxxxxxxx> wrote:
Previously Franklin <franksays@xxxxxxxxxx> wrote:
On 11 Mar 2007, Rod Speed <rod.speed.aaa@xxxxxxxxx> wrote:

Franklin <franksays@xxxxxxxxxx> wrote:
On 11 Mar 2007, Rod Speed <rod.speed.aaa@xxxxxxxxx> wrote:

Franklin <franksays@xxxxxxxxxx> wrote:

I run XP Pro.

I might need to copy some data files (say 50 GB) from one
partition to another. PerfectDisk's ANALYZE option shows that
the files in the target partition have a lot of directory
fragmentation.

No such animal as 'directory fragmentation'

Yes, I am not too sure quite what this refers to. It may be
just the confusing way PerfectDisk reports its analysis. Whatever its term it seems to be
represented by green boxes in
PerfectDisk and these green boxes get very splattered around
after new files (say 100 MB) have been downloaded from the Net.

It seems to be some sort of index fragmentation but somehow it
is not shown as part of the MFT or as part of other NTFS
metadata.

Are there any file copiers which do not fragment the target
data so heavily?

The fragmentation is the result of the state of the destination
drive before the copy happens, not what is used to do the copy.

Time to wake up, smell the coffee, and notice that
fragmentation cant even be detected in a proper double blind
trial except in the most exceptional circumstances and that
isnt normally seen with personal desktop systems.


I know I know I know! Heh! That's what I understand theory and
common sense say. And yet ...

I find defragging does help.

Bet thats an illusion and you wouldnt be able to pick it in a
double blind trial.

Very few situations on a personal desktop system where
the extra seeks between fragments will even be noticeable.

Maybe it's to do with the fact that many of my disks are too
full (85% or more).

Nope, that just affects how much fragmentation occurs, and a
decent file system doesnt fragment too badly even at that level,
unless the files being copied to it are a large percentage of
that 15% thats free.


Am currently sorting that out and am migrating data.
This is why I posted as I was interested in getting the
data into its new position in as tidy condition as possible.

Thats a file system attribute, not what is used to do the copy.

Rod, I was thinking that some copy utilities might use only a
single thread or stream (rather than try and be quick with
multiple threads).

I see parms can be set in copiers like this one
http://www.copyhandler.com/en/manual/configuration.html
and I guessed wildly that a copy app for me would not use buffers
of such a size which dump data onto the target drive in a way that
a single buffer-load causes the data to completely fill some
clusters and then go and put the rest of the buffer-data
elsewhere. Maybe my wild guess about what may happen is just too
wild! :-)

It is. Cluster allocation is an OS task. It cannot really be
bypassed.

That is just plain wrong. Obviously defraggers manage to do it fine.

Defraggers are not possible without direct OS support for them or
without disconnecting (unmounting) the partition from the OS before
defragging. Anything else would result in complete destruction of
the data.

Fact remains, your claim that cluster allocation is an OS task and
cannot be bypassed is just plain wrong when defraggers do just that.

AND there are some real time defraggers around that dont require that
the drive be unmounted for it to be defragged.

Read a book on OS design some time, especially the filesystem
buffer-cache layer. The hoops an OS has to jump through to allow
for filesystem defragmentation while it is mounted are astonishing.
It is still possible though and the defragger has to tell the
OS exactly what it is doing every step of the way.

Arno


.

Relevant Pages

  • Re: Before ReInstall Of WinXP & Games
    ... Have a partition for games... ... Defragging a HDD is overrated. ... you defrag file system. ... to fragmentation however defragmentation was fixing virtually all problems. ...
    (comp.sys.ibm.pc.games.rpg)
  • Re: Re: Cant Defrag Ext3 File System-No Problem!
    ... about defragging a linux system. ... On ext3 filesystems with some fairly regular use ... This means that 5% fragmentation on an ext3 fs means basically nothing, ...
    (Debian-User)
  • Re: Disk defragger besides Norton?
    ... On what basis do you say that "defragging has little value on most ... PCs"? ... none of the partitions approach half full, ... this isn't a swap file fragmentation problem. ...
    (microsoft.public.windowsxp.hardware)
  • Re: Before ReInstall Of WinXP & Games
    ... Have a partition for games... ... Defragging a HDD is overrated. ... you defrag file system. ... to fragmentation however defragmentation was fixing virtually all problems. ...
    (comp.sys.ibm.pc.games.rpg)
  • Re: Question about fragmentation and moving folders . . .
    ... My question is: Will this cause fragmentation? ... use a stopwatch to notice any difference in speed, ... (I'm now bracing myself for the backlash from the defragging ... It does not care in the least where on the disk it finds the ...
    (microsoft.public.win2000.file_system)