sar bug?

[Tim Mooney]

In regard to: sar bug?, Chet Nichols III said (at 2:48pm on Apr 29, 2008):

> hey there-
>
> anyone ever seen a bug in sar where it will start spitting out incorrect
> values? we're running on 32bit intels. an example:
>
> 06:40:13 PM     IFACE   rxpck/s   txpck/s   rxbyt/s   txbyt/s   rxcmp/s
> txcmp/s  rxmcst/s
> 06:40:18 PM        lo      0.00      0.00      0.00      0.00      0.00
> 0.00      0.00
> 06:40:18 PM      eth0 307775.86 390641.38 66821927.59 460472182.76
> 0.00      0.00      0.00
> 06:40:18 PM      eth1      0.00      0.00      0.00      0.00      0.00
> 0.00      0.00
> 06:40:18 PM      sit0      0.00      0.00      0.00      0.00      0.00
> 0.00      0.00

That's funny, I was just going to send an email to the list 
about a similar issue.  I opened a bug about it:

 	https://bugzilla.redhat.com/show_bug.cgi?id=443190

The problem for us is that we're not running the stock kernel, so I don't
think Red Hat is going to be too sympathetic.  Are you using the stock
kernel?  If so, maybe you want to add your name to that bug.

Our main complaint is with the disk I/O statistics -- I modified the sysstat
cron job to also save disk statistics, and sar frequently reports spurious
values when reporting on the collected sa data.  This happens even using
iostat interactively, though, so it's not just the data that's recorded
by sadc.

The sysstat FAQ says it's a kernel bug, but I'm puzzled why it's been
allowed to persist for so long, if it's a known kernel bug.

Tim
-- 
Tim Mooney                                        Tim.Mooney at ndsu.edu
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