Bug 449097

Summary: [NetApp 5.3 bug] multipathd holds the mounted logical volmes open on restart
Product: Red Hat Enterprise Linux 5 Reporter: Rajashekhar M A <rajashekhar.a>
Component: device-mapper-multipathAssignee: Ben Marzinski <bmarzins>
Status: CLOSED ERRATA QA Contact: Cluster QE <mspqa-list>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.2CC: agk, andriusb, bmarzins, bmr, christophe.varoqui, cmarthal, coughlan, cward, dwysocha, edamato, egoggin, heinzm, junichi.nomura, kueda, lmb, marting, mbroz, naveenr, prockai, rajashekhar.a, rsarraf, tao, tranlan, xdl-redhat-bugzilla
Target Milestone: rcKeywords: OtherQA
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2009-01-20 22:08:55 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 373081    
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Description Flags
Terminal logs - has multipath.conf and lvdisplay outputs. none

Description Rajashekhar M A 2008-05-30 12:19:03 UTC 
Description of problem:

On RHEL 5.2 host, when multipathd is restarted, with some logical volumes
mounted, the daemon holds the mounted lvs open. As a result, the open count does
not reduce to zero even after we unmount the LVs and the LVs are not in use.

Version-Release number of selected component (if applicable):

OS: RHEL 5.2 GA

# rpm -qa  | grep device
device-mapper-1.02.24-1.el5
device-mapper-multipath-0.4.7-17.el5
device-mapper-event-1.02.24-1.el5
device-mapper-1.02.24-1.el5
#

How reproducible:
Always

Steps to Reproduce:

1. Create a logical volume on a few LUNs.
2. Create a file system on the lv and mount it to a mountpiont.
3. Check lvdisplay output - should display open count as 1.
4. Restart the multipathd daemon.
5. Unmount the lv from the mountpoint.
6. Check the output of lvdisplay.

Actual results:

The open count is still shown as 1 since the multipathd now holds it.

Expected results:

The multipathd should not hold it open.

Additional info:

1. We hit this issue if we add the automount entry in the /etc/fstab and reboot
the machine. After the machine is booted, we unmount the lv from its mount
point. Now, if we check the open count using lvdisplay, the count is still 1.

Open count reduces to zero after restarting the daemon with the lv unmounted.
The daemon holds only the mounted LVs open.

2. I have attached a file which has terminal logs.
Comment 1 Rajashekhar M A 2008-05-30 12:19:03 UTC 
Created attachment 307191 [details]
Terminal logs - has multipath.conf and lvdisplay outputs.
Comment 3 Ben Marzinski 2008-09-12 23:54:01 UTC 
In order to deal with root device failures, multipathd creates its own namespace, and copies all the necessary callout functions to a ramfs.  However this was creating duplicate mounts in the new namespace for every device that was mounted when multipathd started, which would only get cleaned up when multipathd stopped.  Multipathd now unmounts all of the unneeded mounts from its own namespace on startup.
Comment 6 Naveen Reddy 2008-10-29 16:12:30 UTC 
I have verified this in RHEL5.3 Beta and the open count is shown correctly.
This issue is fixed.

Thank you
Naveen
Comment 9 errata-xmlrpc 2009-01-20 22:08:55 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/RHEA-2009-0232.html