Project Home
Project Home		 Documents
Documents		 Wiki
Wiki		 Discussion Forums
Discussions		 Project Information
Project Info
QNX Operating System/Discussion/OSTech/Sporadic File corruption with cp command. /List of Posts
Forum Topic - Sporadic File corruption with cp command. : (3 Items)
   
Update
Ankur Tibrewal
02/24/2016 1:51 AM
post115861
Sporadic File corruption with cp command.   
Hi, 

We are seeing sporadic file corruption when doing a recursive copy of some files to an ETFS file system. The corruption 
is oftern limited to just one byte. 
It is to be noted that the issue is not seen when doing a file by file copy, only when doing a recursive copy of the 
complete directory. 

It was noticed that the occurrence of this issue reduced when we used cp with "-B" setting. 

Is there a significant difference with using a small copy buffer ? How else should we investigate this problem ?
Kevin Stallard(deleted)
03/02/2016 5:30 PM
post115894
Re: Sporadic File corruption with cp command.   
I bet it is a file system thing, or a device problem (most likely a device problem). 

cp is pretty straight forward and doesn't change behavior because of a different file system.  

I personally would need to have hands on this to see what was going on.  There are things you can do to "intercept" cp's
 copying in QNX to do some top level validation.
Kevin Stallard(deleted)
03/05/2016 9:31 AM
post115917
Re: Sporadic File corruption with cp command.   
Ankur,

I've been pondering your problem, let me give you a data point that may help you move this forward.  The source code for
 the cp utility has been around for 20+ years.  I don't think it was re-written with the advent of QNX 6,  it was around
 with QNX 4.

This utility is being used on literally millions of QNX installations around the world.  I really don't think you have a
 problem there.

Feel free to reach out to me if you want to discuss it some more.

Thanks
Kevin

Return


  A subsidiary of BlackBerry             All content ©2004-2013, QNX Software Systems