HP Serviceguard Extended Distance Cluster for Linux A.12.00.00 Deployment Guide, March 2014

7 Troubleshooting
This chapter describes how to troubleshoot issues related to serviceguard-xdc package.
7.1 Troubleshooting serviceguard-xdc packages
Symptom:
/dev/hpdev/mylink-sde cannot be added to /dev/md0 which means /dev/md0 is running
with only one mirror half. The following message is logged into the package log file:
mdadm: /dev/hpdev/mylink-sde reports being an active member for /dev/md0, but a --re-add fails.
mdadm: not performing --add as that would convert /dev/hpdev/mylink-sde in to a spare.
mdadm: To make this a spare, use "mdadm --zero-superblock /dev/hpdev/mylink-sde" first.
This issue is seen only on SUSE Linux Enterprise Server 11 SP2.
Problem Description:
When a package (P1) is running on a node (Node 1). The package uses a mirror (md0) that
consists of two corresponding mirror half. S1 (local to /dev/hpdev/mylink-sde) and S2
(/dev/hpdev/mylink-sdf local to Node 2). Access to S1 is lost from both nodes, either due
to the power failure to S1 or loss of FC links to S1. Once you restore the power to S1, or restore
the FC links to S1, the corresponding mirror half of S1 (/dev/hpdev/mylink-sde) is accessible
from Node 1.
NOTE: The log message is seen only on SUSE Linux Enterprise Server 11 SP2.
Workaround:
1. Ensure that the link to /dev/hpdev/mylink-sde exists:
#ll /dev/hpdev/mylink-sde
2. If the link to /dev/hpdev/mylink-sde does not exist, run the following command:
#udevadm trigger
3. Confirm that the link to /dev/hpdev/mylink-sde exists:
#ll /dev/hpdev/mylink-sde
lrwxrwxrwx 1 root root 3 Aug 10 11:36 /dev/hpdev/mylink-sde ->../sde
If you still see the log message being logged after rectifying the udev links, there is an issue with
mdadm --add command. To resolve the mdadm --add issue, run the following command:
mdadm --zero-superblock /dev/hpdev/mylink-sde
For more information about mdadm –-zero-superblock, see the mdadm(8) Linux manpage.
For more information about log message, see the novell bugzilla ID 791245 at https://
bugzilla.novell.com/show_bug.cgi?id=791245.
7.2 Troubleshooting VxVM Mirroring Package
• Symptom:
The following message is logged in the package log file:
WARNING: myvol-01 is DISABLED. Please rectify the issue.
WARNING: dg_dd0 is no longer mirrored.
Serviceguard Alert message sent to: [e-mail]
Problem Description:
7.1 Troubleshooting serviceguard-xdc packages 47