Summary:
RHEL 8.7 kernel logs a warning message in syslog and triggers kernel taint when a remote disk is disconnected. No reliability impact is expected.
Symptoms:
When a remote disk is disconnected the following messages followed by the call trace will be logged in syslog:
Oct 17 12:55:50 rac1 kernel: workqueue: WQ_MEM_RECLAIM iscsi_ctrl_5:6:__iscsi_unbind_session [scsi_transport_iscsi] is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn
Oct 17 12:55:50 rac1 kernel: WARNING: CPU: 3 PID: 465 at kernel/workqueue.c:2617 check_flush_dependency+0x114/0x130
flashgrid-health-check command will show a warning about kernel taint.
Affected products:
- FlashGrid Cluster running on RHEL 8 or Oracle Linux 8 with RHCK kernel
- FlashGrid Storage Fabric running on RHEL 8 or Oracle Linux 8 with RHCK kernel
Affected versions:
RHEL 8 (or Oracle Linux 8 with RHCK kernel) after updating to 8.7 kernel version 4.18.0-425.3.1.el8 or newer
Root cause:
Bug in the OS kernel
Resolution:
FlashGrid is working with Red Hat to identify a fix
Workarounds:
- Do not update OS to version 8.7 until the issue is resolved
- If OS must be updated then exclude kernel update
- Oracle Linux 8 users may switch to UEKR6 kernel
- Customers already running the affected kernel version may choose to ignore the warnings. No reliability impact is expected.