Wrong disk space useage


A

Alex Clark

Hi All,

OS is XP Pro x64, fully patched up.

I've just swapped out my secondary hard drive, a 320GB, for a brand new
1.5TB disc. My old disc was nearly full, roughly 10GB free - so 310GB of
data. It was just a data disc and I simply copied all files from the old
320GB to the new 1.5TB (which took a couple of hours). Then I noticed
something very odd...

The new drive is reporting that 658GB of space has been *used*. No
compression was or is in use on any of my hard drives. I've defragged it
and it still reports the same value. I cannot physically have copied more
than 320GB of data onto this new disc, so...


How has my data suddenly doubled in size?


Thanks,
Alex Clark
 
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J

JS

How many files would you say were
copy from old to new drive?

Check the cluster size on your new drive
and compare it to the cluster size on the old drive.
 
G

Gerry

Alex

Do you have System Restore monitoring the new drive? If yes turn it off
as System Restore should only be monitoring the partition containing the
Windows operating system.

What is the cluster size of the original drive and what is it for the
new drive?

--



Hope this helps.

Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~
 
A

Alex Clark

Hi Gerry,
Do you have System Restore monitoring the new drive? If yes turn it off as
System Restore should only be monitoring the partition containing the
Windows operating system.

Done, and then ran disk cleanup to delete all but the most recent
sys-restore point. No change in used space. :-(

What is the cluster size of the original drive and what is it for the new
drive?

4,096 for both.

Thanks,
Alex
 
A

Alex Clark

JS said:
How many files would you say were
copy from old to new drive?

According to the file/folder properties, 282,729 files across 42,008
folders.

Size on disk = 285GB.

Cluster size on old & new drives is 4096.

I'd love for Windows to tell me where that other 400GB is being used up, as
I'd quite like to have it back...
 
J

JS

Its lost because: 282,729 files x 4096 cluster size.
282,729 x 4096/2 = 579,028,992

The general rule of thumb is that for each file
saved on the hard drive one half of one cluster is
lost per file and considered wasted space.
This value varies depending on the each files actual size.

For instance if you had 282,729 files and each file
was exactly one byte in size you would expect that
only 282,729 KB was used on the drive but in fact
282,729 x 4096 in space would be used as the
smallest unit of space a single file can occupy is
one cluster (4096).
 
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P

Pop`

Alex said:
Hi All,

OS is XP Pro x64, fully patched up.

I've just swapped out my secondary hard drive, a 320GB, for a brand
new 1.5TB disc. My old disc was nearly full, roughly 10GB free - so
310GB of data. It was just a data disc and I simply copied all files
from the old 320GB to the new 1.5TB (which took a couple of hours).
Then I noticed something very odd...

The new drive is reporting that 658GB of space has been *used*. No
compression was or is in use on any of my hard drives. I've
defragged it and it still reports the same value. I cannot
physically have copied more than 320GB of data onto this new disc,
so...

How has my data suddenly doubled in size?


Thanks,
Alex Clark

1. 1.5 TB will not give you 1.5 TB of space, as with any drive. So
there is a bunch lost there. the 1.5 TB disks are often actually two
750 Gig disks these days and the lost space will be even higher than if
it were a 1.5 TB single disk inside.
e.g. my Seagate 1 TB drive has 981 Gig available. The preinstalled
software took up another ten or so Gigs, forget just how much. So first
you need to figure out those numbers. Usually Properties will give it
to you.

2. Did pre-installed software come onthe drive? Often it does
nowadays. On mine that was anothe ten gig, but I don't use it, so I
deleted it right away and don't use the mfg supplied toys, preferring my
own.

3. Don't forget the differences in reporting space: be sure to use the
SAME program or a "K" could be either 1,000 or 1,024 bytes. Over Gigs,
that difference gets huge in a hurry.

4. Are you sure XP didn't identify many of the files as "old" due to
non-use, and automagically copressed them for you? They won't be
compresed on the new drive.
Unless you turned it off, you can tell XP compressed files by their
blue color in Explorer. IF you haven't turned that fature off.

5. Sounds like sector sizes are the same. Are they both the same File
System? e.g. both FAT or both NTFS? That can create a difference.
Many drives come preformatted for FAT rather than NTFS for compatability
with the widest range of computer systems. Dumb, IMO; they should come
as NTFS, or let me format them period.

There is probably more, but that's all I can think of at the moment.
The figures you give do sound "funny" and worth figuring out why the
difference, but if the drive is working there is very likely a
reasonable explanation.

Try a test: Send an uncompressed, certain sized file to the hard drive.
Does its file size on the external match that on the internal? Compare
a few more files on the external to the size of the files on the
internal, and see if they are indicating the right size.
Don't sweat small differences because how they hit the sectors can
cause that (e.g. 1 byte needs a full sector (4096), most of the time.
So up to say 8k should be OK, but not of the magnitude you have.

When you come back, give more specs than you did this time.

Hope you'll let us know what you work out,

Twayne
 
A

Alex Clark

Pop` said:
1. 1.5 TB will not give you 1.5 TB of space, as with any drive. So there
is a bunch lost there. the 1.5 TB disks are often actually two 750 Gig
disks these days and the lost space will be even higher than if it were a
1.5 TB single disk inside.

I know, but that wasn't the issue - the issue was with the used space, not
the free space. The discrepancy was huge, i.e. double what the original
data was.

No pre-installed software.

Space on disk used by my files is 285GB.

I believe the discrepancy has been explained though: running a quick Chkdsk
has shown about 300GB worth of bad sectors.

So to summarise, it's getting RMA'd ASAP...

Thanks,
Alex
 
A

Alex Clark

Nope, I found the problem after a chkdsk: 300GB worth of bad sectors.

Disc is getting RMA'd and hopefully swapped out next week.
 
A

Alex Clark

Great. Looks like SeaGate have suddenly lost their rep for building decent
drives, and this is after I just sold a 1TB to my father in law for all his
pictures & music. That's going to be fun if the disc fails in the next
month or so!

From what I gather on that forum they're replacing with refurbs as well.
Guess I'm probably going to have to take my chances...
 
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R

R. McCarty

Certain models of the 7200.11 family seem to be less likely to have
the Firmware issue. CC1H on the ST31000333AS is supposed to
be unaffected. I'm actually waiting on a RMA'd 750-Gigabyte to be
delivered. No way that will go in any production machine until I've
ran a number of test tools on it. One thing to watch is the SMART
table stats on any Seagate drive. Especially keep an eye on the value
of the Reallocated Sectors count.

All in all a colossal mess for Seagate and their reputation.
 
K

Ken Blake, MVP

1. 1.5 TB will not give you 1.5 TB of space, as with any drive. So
there is a bunch lost there. the 1.5 TB disks are often actually two
750 Gig disks these days and the lost space will be even higher than if
it were a 1.5 TB single disk inside.
e.g. my Seagate 1 TB drive has 981 Gig available.



Two points:

1. This has nothing to do with two drives vs. one drive, and it's not
a matter of "lost" space.

2. All hard drive manufacturers define 1GB as 1,000,000,000 bytes,
while the rest of the computer world, including Windows, defines it as
2 to the 30th power (1,073,741,824) bytes. So, for example, a 120
billion byte drive is actually a little under 112GB. Some people point
out that the official international standard defines the "G" of GB as
one billion, not 1,073,741,824. Correct though they are, using the
binary value of GB is so well established in the computer world that I
consider using the decimal value of a billion to be deceptive
marketing.

With respect to a terabyte, exactly the same is true. The disk
manufacturers define it as 1,000,000,000,000 bytes, while the rest of
the computer world, including Windows, defines it as 2 to the 40th
power (1,099,511,627,776) bytes.
 
A

Alex Clark

Mine had the CC1J, according to the label, but apparently that did it no
good.

I've completely reformatted the drive and it's still showing close to 400GB
used space. Chkdsk again reports well over 300M kb allocated to bad
clusters. Looks to me like an entire platter has failed.

Running SeaTools right now and, surprise surprise, no errors found on the
checks so far. SMART showed a successful test on the drive, and it's
running a Long DST right now. Hopefully that'll come up with a strong
indicator of something wrong, because I don't want to have to haggle with
SeaGate when I return this to them and they say "All our tests show it's
working fine!".

Anyone had any experience with the new WD 2TB drives? I might consider
trying for a refund and getting one of those if their reliability record is
a bit better.
 
R

R. McCarty

RMA is done totally over the web. Validation only requires a valid
Serial #. However you have to pay to send the drive back to the
Seagate RMA center in Texas. Actually the turn-around time is less
than a week. Return drive is sent UPS (Signature Required), but it's
a "Factory Refurbished" with a new 5-year warranty.
 
G

Gerry

JS

What you say surely applies equally to both drives and so it would not
cause any discrepancy.

--



Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~
 
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A

Alex Clark

Which is great, so long as that doesn't fail as well. I need to free up my
old drive for another build, but I'm scared to death of formatting that and
then losing *everything* if the new SeaGate fails a month or two down the
line. Apparently SeaGate are charging $120 for data recovery services as
well, even if it's *their* bloody fault the drive failed under warranty!

Fairly disappointing really, I'd always trusted SeaGate as being a reliable
manufacturer of discs. :-(
 
A

Alex Clark

Well now this is just the darndest thing...

All the SeaGate SeaTools diagnostics report nothing wrong. I deleted the
partition and then reformatted but this time I did a Quick Format.
Naturally, this now told me that all 1.36TB was free - no sign of 400GB
allocated to bad sectors, as I would expect.

Confident that I could then cause things to lock-up/crash/throw-errors if I
was to write data to those bad areas, I proceeded to fill the disc up with
hundreds of 3GB+ ISO files (copies of the same file, actually). I actually
copied the file side-by-side on the disc, causing it to read the entire file
and then re-write it. I did this over and over, expecting it to finally
break.

Surely once it got to less than 400GB free space, something had to go wrong,
right? I mean Windows told me that 400GB of space was taken up with bad
sectors, so by then some data would have to be encroaching on that bad area.

I now have a shade over 1GB free space, and no problems. All the ISO files
copied and recopied without a single glitch.

I ran a quick chkdsk (without /F) and it showed no bad sectors at all. I
randomly checked the CRC of at least a dozen of those ISO files, everything
from the original file down to some of the last ones to be written. All of
them checked out perfectly.

I'm currently running a chkdsk with /R to scan all sectors, and am setting
up a batch file to test the CRC of *every* ISO file on there to ensure they
all match.

So what gives? Is the disc really broken, or is Windows XP playing mind
games with me? Could something have caused the Full Format to believe the
disc had 400GB bad sectors when it really didn't? Should I really be
RMA'ing this thing?


Any ideas, anybody?

Thanks,
Alex Clark
 
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