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:
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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
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