slyphnier

Random CRC different when copying to External Drives

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hello everyone

i need some information here

my issue is when i am copying from internal drives (Caviar Black) to external drives Mybook Studio II 2TB (1TB@RAID-1) and Mybook Studio (1.5TB)

when i check the CRC/MD5 using hashcalc sometimes i got different CRC, the properties showing same exact bite

Mybook Studio II seems get different CRC (CRC-fail) more often than Mybook Studio 1.5TB

i am testing movie files... it play without problem (i haven't check throughly whether there broken frame/sound)

i also already tried with different USB port also E-Sata port

it still giving the same issue

For added information :

SMART status all fine

CHKDSK show okay (no bad sector)

my predictions sofar seems related to auto power-save ... which can be set on Mybook Studio 1.5TB series... but not Mybook Studio II

it seems when i start copying files, it powerup so it effect the copy process

i also have Unbranded external case which i use with Seagate 500GB... somehow rarely cause CRC-Fail

copying between internal drives seems not effected to this issue

my questions are :

is RAID1 causing this issue ? as CRC-fail more often on RAID1 mybook one

is this OS issue ? i am using windows7 64bit

is there fix for this ? maybe someone ever got this issue and got it sorted out someway

i am hoping someone can share information regarding this issue

thanks in advance for everyone willing to share their time

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Is it file size related? Are you seeing it on very large transfers and maybe not smaller transfers? If the hash is changing then somehow your file is geting tweaked as it goes over the interface. That shouldn't happen...

Any other issues with your computer as a whole? Any odd errors, and driver conflcits? Any memory errors? Memtest might be suggested to see if there are any errors that come up. If files are moving in and our of bad RAM you might be seeing some errors crop up during the transfer.

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Is it file size related? Are you seeing it on very large transfers and maybe not smaller transfers? If the hash is changing then somehow your file is geting tweaked as it goes over the interface. That shouldn't happen...

Any other issues with your computer as a whole? Any odd errors, and driver conflcits? Any memory errors? Memtest might be suggested to see if there are any errors that come up. If files are moving in and our of bad RAM you might be seeing some errors crop up during the transfer.

thanks for the reply

- the file size (on the properties) it showing same size

- yes it seems large transfer files prone to the issue more than small files

- yes the only issue is hash different from the source

as for my computer, everything run stable... chkdsk show no badsector, because its wd drives i also test using wddiag and no problem either

i done memtest for 6hours or so ... the result was ok (no errors)

i already tried looking regarding this on google... and the only things i ever find is :

http://searchwindowsserver.techtarget.com/tip/External-USB-drives-may-have-silent-CRC-error-failures

but it didn't give any answer beside telling the issue

Edited by slyphnier

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How are you copying the files to the external drives? If you're using a backup utility, there's a chance that it might be changing the file's modification date. Any change to the modification date could cause your hash to change as well, depending on the utility. The current version of HashCalc correctly hashes only the content, so it's unlikely that the date would change the hash. I would recommend using robocopy to ensure that all of the file's attributes remain the same.

I'm assuming that all filesystems in question are NTFS, correct?

Can you replicate the issue using a different utility, such as Checksum? If not, it may be a bug in the version of hashcalc that you are using. Is that up to date?

edit: I tested HashCalc on my own x86-64 system and found no issues between volumes or with changed modification dates

Edited by MPond

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How are you copying the files to the external drives? If you're using a backup utility, there's a chance that it might be changing the file's modification date. Any change to the modification date could cause your hash to change as well, depending on the utility. The current version of HashCalc correctly hashes only the content, so it's unlikely that the date would change the hash. I would recommend using robocopy to ensure that all of the file's attributes remain the same.

I'm assuming that all filesystems in question are NTFS, correct?

Can you replicate the issue using a different utility, such as Checksum? If not, it may be a bug in the version of hashcalc that you are using. Is that up to date?

edit: I tested HashCalc on my own x86-64 system and found no issues between volumes or with changed modification dates

hello

i manually copy (copy and paste) in explorer

and i am using the latest hashcalc (ver2.02)

from what i see... the crc-fail seems only when copying large files (more than 300mb size)

small size file seems not effected

for automatic backup, i am using goodsync (www.goodsync.com), i didn't check every single files... but seems everythings okay

as no error/failure notice from goodsync either

*i am not using goodsync for moving big files though, i use goodsync to sync windows user data mostly

and yes, all in NTFS

i will try checksum and will post update

i don't know if this have relation or not, but seems WDFME.exe (WD file management engine) might making the issue

many people already have issue with it, it taking lots resources, from what i see its more like keep reading / checking something in hdd thus lagging everything

since few days i "process end" it from taskbar when i log to windows, but i still need to check if disable wdfme.exe solve my issue or not

the only things why i don't remove WDFME (that comes with WD Smartware) is because its more like driver

without that, i dont know why but windows wont let me detect my external drive... it will end unknown device

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Hello,

can you tell us what is your PC hardware configuration. I had similar problems but with internal disks copy about year ago.

link

my current hardware

i7 950 (stock speed)

6GB corsair C7

gigabyte GA-X58-UD7 rev.2

Radeon 5850

asus xonar d2x

corsair AX750 PSU

windows7 ultimate 64bit

if my memory right, i been aware this issue since my last pc

intel Q9550

4GB ram

dell foxcon nvidia chipset board

nvidia 9800GT

dell psu

vista 32bit

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