Try changing your console= entry in grub to S1 or S2. We have some supermicro nodes using S1 and some that use S2 depending on server age.
Jeff Jeffrey R. Lang Advanced Research Computing Center University of Wyoming, Information Technology Center 1000 E. University Ave Laramie, WY 82071 Email: jrl...@uwyo.edu Work: 307.766.3381 From: Marcos Melo <marcos.mk.m...@gmail.com> Sent: Friday, May 23, 2025 12:12 PM To: xcat-user@lists.sourceforge.net Subject: [xcat-user] rcons - SOL does not show kernel output after GRUB on Supermicro AS -1024US-TRT using xCAT 2.16.5 (UEFI + Oracle Linux 8.8) ◆ This message was sent from a non-UWYO address. Please exercise caution when clicking links or opening attachments from external sources. Hi everyone, I’m having trouble using rcons via goconserver on Supermicro AS -1024US-TRT servers running with xCAT 2.16.5 and Oracle Linux 8.8, booting in UEFI mode with BLS enabled. The issue is that after the GRUB menu, the SOL (Serial Over LAN) console goes black and doesn’t show any kernel messages or login prompt via rcons. The BIOS POST and GRUB appear just fine. Below is the full setup to give context. I’d appreciate any tips or if someone has faced a similar issue. Environment: · Server: Supermicro AS -1024US-TRT · BMC: AST2500 · BIOS with SOL over COM1 · xCAT: 2.16.5 · Headnode OS: Oracle Linux 8.8 · Node OS: Oracle Linux 8.8 · Boot mode: UEFI with BLS (/boot/loader/entries/) · IPMI management: cons=ipmi, mgt=ipmi · rcons backend: goconserver BIOS: · COM1 Console Redirection: Enabled · SOL Redirection: Enabled · Redirection After BIOS POST: Always Enable · Legacy Serial Redirection Port: COM1 · Baud Rate: 115200 · Terminal Type: VT100+ GRUB (/etc/default/grub): GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL="serial console" GRUB_SERIAL_COMMAND="serial --speed=115200" GRUB_CMDLINE_LINUX="crashkernel=auto rd.md.uuid=852f7037:11485f13:1661da7f:6319b34d rd.md.uuid=0e85274f:6be9a886:94b8e24f:12755dae console=ttyS0,115200" GRUB_DISABLE_RECOVERY="true" GRUB_ENABLE_BLSCFG=true serial-getty is running: serial-getty@ttyS0.service<mailto:serial-getty@ttyS0.service> - Serial Getty on ttyS0 Loaded: loaded (/usr/lib/systemd/system/serial-getty@.service<mailto:/usr/lib/systemd/system/serial-getty@.service>; enabled-runtime; vendor preset: disabled) Active: active (running) since Fri 2025-05-16 17:09:06 -03; 5 days ago Docs: man:agetty(8) man:systemd-getty-generator(8) http://0pointer.de/blog/projects/serial-console.html Main PID: 5679 (agetty) Tasks: 1 (limit: 2884372) Memory: 308.0K CGroup: /system.slice/system-serial\x2dgetty.slice/serial-getty@ttyS0.service └─5679 /sbin/agetty -o -p -- \u --keep-baud 115200,38400,9600 ttyS0 vt220 May 16 17:09:06 localhost.localdomain systemd[1]: Started Serial Getty on ttyS0 Serial device detected by the kernel, dmesg | grep tty: [ 0.000000] Command line: BOOT_IMAGE=(mduuid/0e85274f6be9a88694b8e24f12755dae)/vmlinuz-4.18.0-477.21.1.el8_8.x86_64 root=UUID=fa4950bb-e48d-422a-8a46-0e05ae3235ff ro crashkernel=auto rd.md.uuid=852f7037:11485f13:1661da7f:6319b34d rd.md.uuid=0e85274f:6be9a886:94b8e24f:12755dae console=ttyS0,115200 [ 0.000000] Kernel command line: BOOT_IMAGE=(mduuid/0e85274f6be9a88694b8e24f12755dae)/vmlinuz-4.18.0-477.21.1.el8_8.x86_64 root=UUID=fa4950bb-e48d-422a-8a46-0e05ae3235ff ro crashkernel=auto rd.md.uuid=852f7037:11485f13:1661da7f:6319b34d rd.md.uuid=0e85274f:6be9a886:94b8e24f:12755dae console=ttyS0,115200 [ 0.001000] printk: console [ttyS0] enabled [ 10.922314] 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A [ 10.950427] 00:04: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A What’s happening: · rcons shows BIOS POST and GRUB normally · After GRUB, the console goes black · No kernel messages or login prompt appear · The system boots fine (verified via SSH and BMC console) · echo "test" > /dev/ttyS0 does not output anything to rcons Questions: 1. Could BLS be preventing the console= parameters from being applied properly to the kernel? 2. Would it be better to disable BLS (GRUB_ENABLE_BLSCFG=false) and use the traditional /boot/grub2/grub.cfg instead? 3. Is there any specific configuration required for goconserver or xCAT to work correctly with Supermicro servers in UEFI mode? 4. Has anyone experienced this issue with Supermicro AST2500 BMCs and serial redirection? Any help or insight would be much appreciated. I can share more logs or test additional changes if needed. Thanks!
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