data corruption

hi there.
For some time now I have been experiencing some data corruption
problems, perhaps intermittently. With large files, I now always get
at least one error when copying large files. E.g. this file is about
1Gbyte:
F:\copy disk.gz copy.gz /v
ERROR Verify - copy.gz
1 file(s) copied.

F:\fc disk.gz copy.gz /b
Comparing files tivodisk.gz and COPY.GZ
1A742DCD: D5 C5
1AA95DCD: 1B 0B
208C5DCD: 5A 4A
2D9B3DCD: FD ED
40BE5DCD: 5E 4E
40F49DCD: 47 57

Curiously, they are always single bit errors (always bit 4 in fact),
while the number of errors varies from 2 to 6 or so.
The same sort of thing happens in XP as in Win98 (it is dual booted)
It seems to be the hard drive -- but is there anything else i should
look at or try?
The disk is a Seagate ST340014A, 80G.
I ran Seagates diagnostic but that didn't turn up anything.

Related question -- Is there a way to make Windows do the equivalent
of the /v switch, e.g. when dropping/dragging in explorer?
Apparently, by default anyway, windows does NOT do a verify after
writing. This problem seems to have taken me forever to track down
because I believed that windows was verifying when in fact it appears
it does not.

Thanks.

On 12 Jul 2004 06:06:44 -0700, (Geek Junk):

but is there anything else i should
look at or try?

The RAM.
Try memtest386. The official site doesn't seem to exist anymore, but
it's part of the Timo Rescue CD http://rescuecd.sourceforge.net/.
D/l and burn the ISO image, reboot on the CD, and choose "memtest386"
on the boot menu.

Have you looked in Event Viewer for any error messages ?

Do a chkdsk /f (reboot if necessary).

Plan on replacing your disk


In article ,
Geek Junk wrote:
hi there.
For some time now I have been experiencing some data corruption
problems, perhaps intermittently. With large files, I now always get
at least one error when copying large files. E.g. this file is about
1Gbyte:
F:\copy disk.gz copy.gz /v
ERROR Verify - copy.gz
1 file(s) copied.

F:\fc disk.gz copy.gz /b
Comparing files tivodisk.gz and COPY.GZ
1A742DCD: D5 C5
1AA95DCD: 1B 0B
208C5DCD: 5A 4A
2D9B3DCD: FD ED
40BE5DCD: 5E 4E
40F49DCD: 47 57

Curiously, they are always single bit errors (always bit 4 in fact),
while the number of errors varies from 2 to 6 or so.
The same sort of thing happens in XP as in Win98 (it is dual booted)
It seems to be the hard drive -- but is there anything else i should
look at or try?
The disk is a Seagate ST340014A, 80G.
I ran Seagates diagnostic but that didn't turn up anything.

Related question -- Is there a way to make Windows do the equivalent
of the /v switch, e.g. when dropping/dragging in explorer?
Apparently, by default anyway, windows does NOT do a verify after
writing. This problem seems to have taken me forever to track down
because I believed that windows was verifying when in fact it appears
it does not.

Thanks.


--
Al Dykes
-----------
adykes at p a n i x . c o m

Previously Fabien LE LEZ wrote:
On 12 Jul 2004 06:06:44 -0700, (Geek Junk):

but is there anything else i should
look at or try?

The RAM.

Yes, the error is _very_ characteristic for a weak bit in RAM.
Als the addresses it turns up in.

Try memtest386. The official site doesn't seem to exist anymore, but

Huh? It is he http://www.memtest86.com/

it's part of the Timo Rescue CD http://rescuecd.sourceforge.net/.
D/l and burn the ISO image, reboot on the CD, and choose "memtest386"
on the boot menu.

Or get the floppy image, copy it onto a floppy disk and just boot from
it. Probably the best software-only memory tester around. I usually
run it for some hours on new PC's or after changing/upgrading RAM.
Saves a lot of trouble.

Arno

--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus

On 12 Jul 2004 20:10:23 GMT, Arno Wagner :

Try memtest386. The official site doesn't seem to exist anymore, but

Huh? It is he http://www.memtest86.com/

Seems that I misspelled it (memtest386) and, since I saw several
references to http://www.memtest386.com on Google, I didn't notice
the typo.

I'd suspect the disk buffer memory.

Check whether last digits of the error location are always the same, across
reboots, and with copy command and copy by Windows Explorer. If it's DCD, as
in your example, the disk buffer is definitely flaky (one particular bit).
You have to replace the whole disk, unfortunately.

"Geek Junk" wrote in message
om...
hi there.
For some time now I have been experiencing some data corruption
problems, perhaps intermittently. With large files, I now always get
at least one error when copying large files. E.g. this file is about
1Gbyte:
F:\copy disk.gz copy.gz /v
ERROR Verify - copy.gz
1 file(s) copied.

F:\fc disk.gz copy.gz /b
Comparing files tivodisk.gz and COPY.GZ
1A742DCD: D5 C5
1AA95DCD: 1B 0B
208C5DCD: 5A 4A
2D9B3DCD: FD ED
40BE5DCD: 5E 4E
40F49DCD: 47 57

Curiously, they are always single bit errors (always bit 4 in fact),
while the number of errors varies from 2 to 6 or so.
The same sort of thing happens in XP as in Win98 (it is dual booted)
It seems to be the hard drive -- but is there anything else i should
look at or try?
The disk is a Seagate ST340014A, 80G.
I ran Seagates diagnostic but that didn't turn up anything.

Related question -- Is there a way to make Windows do the equivalent
of the /v switch, e.g. when dropping/dragging in explorer?
Apparently, by default anyway, windows does NOT do a verify after
writing. This problem seems to have taken me forever to track down
because I believed that windows was verifying when in fact it appears
it does not.

Thanks.

"Alexander Grigoriev" wrote in message k.net...
I'd suspect the disk buffer memory.

Nonsense.


Check whether last digits of the error location are always the same, across
reboots, and with copy command and copy by Windows Explorer. If it's DCD, as
in your example, the disk buffer is definitely flaky (one particular bit).

Ah, diskdrives with 1GB buffers. What next can we expect from you.

If it was the buffer he would see errors at most a (few) megabyte apart,
so in their thousands, not just 6. Even if the 256kB disk buffer rotates
through the cache when the previous diskbuffer converts to a cache
segment you will still find them every 2 or 8 MB, so in their hundreds.

You have to replace the whole disk, unfortunately.

And even that is false as the buffer sits on the EC assembly.
But that's obviously a moot point.


"Geek Junk" wrote in message om...
hi there.
For some time now I have been experiencing some data corruption
problems, perhaps intermittently. With large files, I now always get
at least one error when copying large files. E.g. this file is about
1Gbyte:
F:\copy disk.gz copy.gz /v
ERROR Verify - copy.gz
1 file(s) copied.

F:\fc disk.gz copy.gz /b
Comparing files tivodisk.gz and COPY.GZ
1A742DCD: D5 C5
1AA95DCD: 1B 0B
208C5DCD: 5A 4A
2D9B3DCD: FD ED
40BE5DCD: 5E 4E
40F49DCD: 47 57

Curiously, they are always single bit errors (always bit 4 in fact),
while the number of errors varies from 2 to 6 or so.
The same sort of thing happens in XP as in Win98 (it is dual booted)
It seems to be the hard drive -- but is there anything else i should
look at or try?
The disk is a Seagate ST340014A, 80G.
I ran Seagates diagnostic but that didn't turn up anything.

Related question -- Is there a way to make Windows do the equivalent
of the /v switch, e.g. when dropping/dragging in explorer?
Apparently, by default anyway, windows does NOT do a verify after
writing. This problem seems to have taken me forever to track down
because I believed that windows was verifying when in fact it appears
it does not.

Thanks.

Fabien LE LEZ wrote in message . ..
On 12 Jul 2004 06:06:44 -0700, (Geek Junk):

but is there anything else i should
look at or try?

The RAM.
Try memtest386. The official site doesn't seem to exist anymore, but
it's part of the Timo Rescue CD http://rescuecd.sourceforge.net/.
D/l and burn the ISO image, reboot on the CD, and choose "memtest386"
on the boot menu.

I was so convinced the problem was the hard drive i ran out and bought
a replacement -- but that didn't fix the problem (that will learn me!)

Yup. It was the memory.
I ended up troubleshooting the problem by pulling SIMMs in and out,
and that
isolated the problem to one of the three SIMMs.

Thanks.
--Ed

On 13 Jul 2004 21:24:45 -0700, (Geek Junk):

Yup. It was the memory.

At work, we bought 6 new (quite low-end) PCs last January. Out of six,
three had slightly defective RAM.
[Decreasing the frequency by a few % was enough to repair the problem
though.]

Previously Geek Junk wrote:
Fabien LE LEZ wrote in message . ..
On 12 Jul 2004 06:06:44 -0700, (Geek Junk):

but is there anything else i should
look at or try?

The RAM.
Try memtest386. The official site doesn't seem to exist anymore, but
it's part of the Timo Rescue CD http://rescuecd.sourceforge.net/.
D/l and burn the ISO image, reboot on the CD, and choose "memtest386"
on the boot menu.

I was so convinced the problem was the hard drive i ran out and bought
a replacement -- but that didn't fix the problem (that will learn me!)

Yup. It was the memory.
I ended up troubleshooting the problem by pulling SIMMs in and out,
and that
isolated the problem to one of the three SIMMs.

That is exactly the right approach. Cons!

Arno
--
For email address: lastname AT tik DOT ee DOT ethz DOT ch
GnuPG: ID:1E25338F FP:0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
"The more corrupt the state, the more numerous the laws" - Tacitus