On RHEL 6.2 get_io_counters returns 0 read bytes and writebytes always, read count is 5234

[giampaolo]

From mahantes...@gmail.com on September 19, 2012 10:22:44

What steps will reproduce the problem?  
1.on RHEL use ps util to moniter a process which writes/reads a file
2.get_io_counters check values 3. 

What is the expected output?  
read_count=X,write_count=Y,read_bytes=Z,write_bytes=B
if X >0, Z should be greater than 0 

What do you see instead?  
read_count=5672,read_bytes=0,write_bytes=0,write_count=0 

What version of psutil are you using? What Python version?  
psutil-0.6.1-py2.6-linux-x86_64, 
Python 2.6.6 ( r266 :84292, Sep 12 2011, 14:03:14)
[GCC 4.4.5 20110214 (Red Hat 4.4.5-6)] on linux2 

On what operating system? Is it 32bit or 64bit version?  
Red Hat Enterprise Linux Server release 6.2, 64Bit Please provide any 
additional information below.

Original issue: http://code.google.com/p/psutil/issues/detail?id=327

[giampaolo]

From g.rodola on September 19, 2012 16:55:43

Are you talking about process IO counters or system IO counters?

> read_count=X,write_count=Y,read_bytes=Z,write_bytes=B
> if X > 0, Z should be greater than 0

That's not necessarily true. A process might be performing read() calls not 
returning any data.
Moreover, the 0 value you see comes directly from the OS, hence even if it's 
not correct (which I doubt) psutil can't do anything about that.

Please try to run the following code:

import psutil
for p in psutil.process_iter():
    try:
        print p.get_io_counters()
    except psutil.Error:
        pass

If read_count of *any* of the enlisted processes is != 0 then it means psutil 
is correctly fetching that information.

[giampaolo]

From g.rodola on December 12, 2012 04:34:07

Closing this out for lack of response.
AFAICT there should be no issue here though.

Status: CantReproduce

[giampaolo]

From g.rodola on March 02, 2013 04:13:03

Updated csets after the SVN -> Mercurial migration: r266 == revision 
f910f2f333cc