Twayne

> "Twayne" <nobody@devnull.spamcop.net> wrote:
>
>> I'm pretty tired and that's actually a complex answer, but, in
>> basics, it's:...
>
> I understand and agree that, for general use on a partition with
> dynamic access, complete free space consolidation is undesirable.

Not talking "dynamic access" hard drives unless you just mean lots of
activity as in changes, rewrites, etc.. Dynamic access is also a kind
of disk structure, pretty unusual to find these days.

>
> However, under some special circumstances, I believe consolidation
> should prove helpful. In the partition I am interested in
> consolidating free space on, the recycle bin and restore points are
> disabled and there is no page file or caches, no extension or other
> modification of existing files, and no dynamic activity. The
> partition is written to perhaps half a dozen times a day, by only one
> program at a time, with new large (multi-GB) files. All files
> written to the partition are backup files of one sort or another.
>
> With free space scattered as usual, a backup file may have >1500
> extents scattered all over the partition. I would expect performance
> would be better if free space were consolidated.

Hmm, dunno; I fail to see how a regular defrag doesn't create enough
free space to allow the data to be contiguous then. It must be writing
the file in chunks (starting/stopping very quickly) or something
because that kind of fragmentation shouldn't normally happen. I can
copy a 7 Gig file to my rendering drive and if I've degragged recently,
it'll be contiguous. Other very large files exist in that partition,
but they have been defragged before the copy. I seldom see much
fragmentation unless I've been using the editing software which creates
many, many huge buffers of files on disk. THAT causes the final product
to go fragmented to a few hundred pieces but not when I copy an original
over there to work on. However, I don't do that anymore; have a drive
specifically for the editing scratchpads now. THAT disk gets terribly
fragmented, but it's from the apps running.
I tried a 2 Gig write to it just now for grins (larger takes too
long) and it's contiguous.
Any chance you have a mix of different speed drives or unequal
buffers or something? That goes instanly out of my league<g>.

Sorry; guess I can't help. >1500 fragments to a defragged drive is
really huge; that would bother me too. Actually, a lot of that info
should have been in your original post.

Twayne

Guy Scharf

"Twayne" <nobody@devnull.spamcop.net> wrote:

> Hmm, dunno; I fail to see how a regular defrag doesn't create
> enough free space to allow the data to be contiguous then.

It would. But a "regular" defrag of the 700GB partition takes at least
12 hours, defragging huge files (up to 70 GB) that, frankly, don't
benefit from being defragmented because they are likely to be discarded
without being read (they are backup files, so not needed except to
recover from problems).

Even trying to defrag the volume more frequently still takes a long
time each time. Which is why I was looking for a quicker way of
consolidating free space.

I just did a "Consolidate Free Space" defragment with PerfectDisk 2008,
followed by a backup of the C drive using True Image Home 10 (creating
a 14 GB file). The file is fragmented into 37 pieces scattered all
over free space (at least as shown by PerfectDisk).

I'm off to do more tests and exploration to see if I can figure out
what is going on.

Guy