Red Hat Bugzilla – Bug 449097
[NetApp 5.3 bug] multipathd holds the mounted logical volmes open on restart
Last modified: 2010-10-22 21:35:40 EDT
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
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.
The open count is still shown as 1 since the multipathd now holds it.
The multipathd should not hold it open.
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.
Created attachment 307191 [details]
Terminal logs - has multipath.conf and lvdisplay outputs.
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.
I have verified this in RHEL5.3 Beta and the open count is shown correctly.
This issue is fixed.
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.