Bug 715300 - statics for TTY devices are not available
Summary: statics for TTY devices are not available
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel-xen
Version: 5.7
Hardware: Unspecified
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Xen Maintainance List
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-06-22 13:52 UTC by Branislav Náter
Modified: 2011-06-29 13:55 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-06-29 13:55:26 UTC
Target Upstream Version:
Embargoed:


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Description Branislav Náter 2011-06-22 13:52:34 UTC
Description of problem:
It's not possible to view statistics for TTY devices using "sar -y" command. sadc is gathering data from files in /proc/tty/driver/ directory. This directory is empty on ia64 machines with xen kernel (2.6.18-238.el5xen in this case). These files exists on ia64 machine with 2.6.18-268.el5 kernel.

Version-Release number of selected component (if applicable):
sysstat-7.0.2-9.el5.ia64
2.6.18-238.el5xen

How reproducible:
always

Steps to Reproduce:
1. install sysstat, start sysstat service
2. run sar -y
  
Actual results:
message "Requested activities not available in file"

Expected results:
Actual tty statistics

Comment 1 Andrew Jones 2011-06-29 09:01:08 UTC
Which specific device(s) are you looking for? When running on xen there's a good chance the device doesn't work, and the substitute device (if there is one) may or may not implement proc handlers.

Comment 2 Branislav Náter 2011-06-29 13:40:37 UTC
I'm looking for this devices:

# cat /proc/tty/driver/serial 
serinfo:1.0 driver revision:
0: uart:16550A mmio:0xFF5E2000 irq:49 tx:0 rx:0
1: uart:16550A mmio:0x88033000 irq:55 tx:2172 rx:0
<snip>

I recently find out that "serial" file is also missing on s390x with regular kernel 2.6.18-238.9.1.el5 but I don't know if this is somehow related to this issue.

Comment 3 Andrew Jones 2011-06-29 13:55:26 UTC
That device won't show up on dom0 kernels (or any paravirt guest kernels, -xen kernels). They use the xen console instead of serial. Only HVM guests will have this device in /proc. I'm closing as not-a-bug.


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