如何在 Red Hat Enterprise Linux 9 中配置 kdump 的 crashkernel 参数？

Issue

• 在配置 crashkernel 参数时，kdump 服务无法启动：

# systemctl status kdump.service 
○ kdump.service - Crash recovery kernel arming
     Loaded: loaded (/usr/lib/systemd/system/kdump.service; enabled; vendor preset: enabled)
     Active: inactive (dead)
  Condition: start condition failed at Wed 2022-01-26 23:28:22 IST; 8s ago
             └─ ConditionKernelCommandLine=crashkernel was not met

Jan 26 23:26:16 localhost systemd[1]: Condition check resulted in Crash recovery kernel arming being skipped.
Jan 26 23:28:22 localhost.localdomain systemd[1]: Condition check resulted in Crash recovery kernel arming being skipped.

• 可以使 kdump 正常工作的正确的 crashkernel 参数是什么？
• 内核崩溃（panics）时出现 "crashkernel reservation failed - memory is in use"