Bug 675058

Summary:	iostat: bogus value appears when device is unmounted/mounted
Product:	Red Hat Enterprise Linux 5	Reporter:	Takuma Umeya <tumeya>
Component:	sysstat	Assignee:	Ivana Varekova <varekova>
Status:	CLOSED ERRATA	QA Contact:	BaseOS QE - Apps <qe-baseos-apps>
Severity:	high	Docs Contact:
Priority:	urgent
Version:	5.5	CC:	bnater, masanari_iida, ovasik, rvokal
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	In previous versions of the iostat utility, the number of NFS mount points was hard-coded. Consequently, various issues occurred while iostat was running and NFS mount points were mounted or unmounted; certain values in iostat reports overflowed and some mount points were not reported at all. With this update, a patch has been provided for iostat to properly recognize when an NFS mount point mounts or unmounts, fixing these issues. See also: 706095, 694767	Story Points:	---
Clone Of:
Clones:	690402 (view as bug list)		Environment:
Last Closed:	2011-07-21 10:41:18 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:
Bug Blocks:	690402

Description Takuma Umeya 2011-02-04 05:12:23 UTC

Description of problem:
When a filesystem partition is unmounted or mounted while iostat -kn is running, iostat reports bogus values. Also if a filesystem partition is mounted while the command is running, iostat seems not be aware of it at all. 

Version-Release number of selected component (if applicable):
sysstart-7.0.2-3.el5

How reproducible:
Always

Steps to Reproduce:
1. mount NFS share
# mount nfs:/share /nfs

2. run iostat
# iostat -kn 1 | grep nfs:/share

3. iostat will report correct value.
nfs:/share 10912.00 0.00 0.00 0.00 10912.00 0.00 341.00 341.00 0.00
nfs:/share 10048.00 0.00 0.00 0.00 10048.00 0.00 314.00 314.00 0.00
nfs:/share 10784.00 0.00 0.00 0.00 10784.00 0.00 337.00 337.00 0.00
nfs:/share 8595.04 0.00 0.00 0.00 8595.04 0.00 268.60 268.60 0.00
nfs:/share 10666.67 0.00 0.00 0.00 10698.04 0.00 333.33 334.31 0.00

4. umount the NF share
# umount /nfs

5. iostat keeps reporting values for non-existing mount point
nfs:/share 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nfs:/share 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nfs:/share 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nfs:/share 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6. re-mount the NFS share
# mount nfs:/share /nfs

7. Now iostat reports correct value though the 1st value looks invalid
nfs:/share 18014398509162156.00 0.00 0.00 0.00 18014398509172004.00 0.00 18446744073709543424.00 18446744073709543424.00 0.00
nfs:/share 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
nfs:/share 0.00 0.00 0.00 0.00
  
Actual results:
iostat is not aware of unmounted filesysem partition; it's not aware of the filesystem partition mounted again; and it's not aware of any filesystem partition mounted while it's running. 

Expected results:
iostat must be umount/mount aware. 

Additional info:

Comment 5 masanari iida 2011-02-28 08:03:06 UTC

Add CC List

Comment 8 Tomas Capek 2011-06-29 08:28:39 UTC

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
In previous versions of the iostat utility, the number of NFS mount points was hard-coded. Consequently, various issues occurred while iostat was running and NFS mount points were mounted or unmounted; certain values in iostat reports overflowed and some mount points were not reported at all. With this update, a patch has been provided for iostat to properly recognize when an NFS mount point mounts or unmounts, fixing these issues.

See also: 706095, 694767

Comment 9 errata-xmlrpc 2011-07-21 10:41:18 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-1005.html