Environment
Novell Open Enterprise Server 11 (OES 11) Linux Support Pack 1
Citrix XenServer 6.2
Citrix XenServer 6.2
Situation
After installing Novell Open Enterprise Server 11 SP1 on a Citrix XENserver, excessive logging with the following characteristics were observed which was flooding syslog :
Sep 2 17:27:54 xenoes11 kernel: [12720874.987538] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled
Sep 2 17:27:54 xenoes11 modprobe: FATAL: Error inserting 8250 (/lib/modules/3.0.80-0.7-xen/kernel/drivers/tty/serial/8250.ko): Cannot allocate memory
Sep 2 17:27:54 xenoes11 kernel: [12720874.987538] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled
Sep 2 17:27:54 xenoes11 modprobe: FATAL: Error inserting 8250 (/lib/modules/3.0.80-0.7-xen/kernel/drivers/tty/serial/8250.ko): Cannot allocate memory
Resolution
Modify the kernel boot parameter for the OES11 SP1 (DomU) server from xencons=ttyS to xencons=hvc1 and reboot.
The 8250 and serial_core modules will now load without any problems.
The 8250 and serial_core modules will now load without any problems.
Cause
Using xencons=ttyS the 8250 serial port fails to initialize, because the TTY major/minor are being held by Dom0
Using xencons=hvc1 Xen registers it's own values for /dev/hvc1 and the 8250 serial port registers the original TTY values.
Using xencons=hvc1 Xen registers it's own values for /dev/hvc1 and the 8250 serial port registers the original TTY values.