IBM Support

Possibility of failure of the kdump operation when an Emulex FC adapter is installed

Flashes (Alerts)


Abstract

On systems with an Emulex FC SAN adapter (lpfc driver) installed, the kernel dump (kdump) operation might not complete.

Content

Linux® Releases Affected
Red Hat® Enterprise Linux 8.2, and later
SUSE Linux Enterprise Server 15, Service Pack 1, and later
SUSE Linux Enterprise Server 12, Service Pack 5

IBM® Systems Affected
All IBM POWER8® and POWER9™ systems with Emulex FC adapters that have feature codes 5273, 5729, 5735, EL2N, EL43, EL58, EL5B, EL5U, EL5V, EL5W, EL5X, EN0A, EN0B, EN1A, EN1B, EN1C, or EN1D.
Description
When a dump operation is not complete, a message similar to the following example is displayed:
INFO: task systemd-shutdown:1 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
systemd-shutdown D    0     1      0 0x00040000
Call Trace:
[c000000102c7b590] [c000000102c7b5e0] 0xc000000102c7b5e0 (unreliable)
[c000000102c7b760] [c00000000801fa60] __switch_to+0x2e0/0x4e0
[c000000102c7b7c0] [c000000008cdaf94] __schedule+0x2c4/0xb20
[c000000102c7b890] [c000000008cdb838] schedule+0x48/0xb0
[c000000102c7b8b0] [c000000008ce11b4] schedule_timeout+0x404/0x540
[c000000102c7b9c0] [c000000008cdcba4] wait_for_common+0x254/0x390
[c000000102c7ba50] [c000000008161958] flush_workqueue+0x158/0x550
[c000000102c7bb00] [c008000002e9b114] lpfc_pci_remove_one+0xaec/0x1080 [lpfc]
[c000000102c7bbc0] [c00000000875dfd8] pci_device_shutdown+0x68/0xe0
[c000000102c7bc00] [c00000000886b3b4] device_shutdown+0x204/0x380
[c000000102c7bca0] [c00000000817562c] sys_reboot+0x14c/0x3c0
[c000000102c7be30] [c00000000800b388] system_call+0x5c/0x70
Workaround
• To work around the issue, you can disable the lpfc module in the kdump command line, if you are not using the Emulex FC SAN adapter as the dump target. You can run the following steps to disable the lpfc module:
1. Edit the  /etc/sysconfig/kdump file and add the argument module_blocklist=lpfc to the KDUMP_COMMANDLINE_APPEND line.
2. Rebuild the kdump kernel from the command line by running the following command:
# touch /etc/kdump.conf
3. Restart the kdump service from the command line by running the following command:
# systemctl restart kdump.service
•  If you prefer to use an lpfc based adapter as a dump target, the configuration of the kdump service must be modified to use all available CPUs during the dump operation. You can run following commands to work around the issue:
1. In the /etc/sysconfig/kdump file, remove the maxcpus=1 parameter from the KDUMP_COMMANDLINE_APPEND line.
2. Rebuild the kdump kernel from the command line by running the following command:
# touch /etc/kdump.conf
3. Restart the kdump service from the command line by running the following command:
# systemctl restart kdump.service
Fix Outlook:
IBM is working with Red Hat, SUSE, and Broadcom to release a fix for this issue. The fix for this issue should come as part of a future RHEL or SLES release. Open a support ticket with Red Hat or SUSE if a hot fix is needed before the next release.
SUSE bug numbers:
1136666
Red Hat bug numbers:
1722596

Related Information

Installing and configuring kdump

[{"Line of Business":{"code":"LOB26","label":"Storage"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SGMV157","label":"IBM Support for Red Hat Enterprise Linux Server"},"ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"All Version(s)"}]

Document Information

Modified date:
17 December 2020

UID

ibm16335221

Page Feedback