Why I did it
On certain routers with baud rate 9600, crash kernel is taking a long time , close to ~5mins, to complete kernel dump and reload the box. On contrast to routers with baud rate 115200, crash kernel dump process is observed to be completed under 35s-60s (depending on the platform). Currently, all debug and informational messages are printed on the console which also factors in for the delay seen. Unless the router is monitored on console in real time, these messages are not very useful. Setting the loglevel to warning will help reduce the verbosity of logs on console, in turn allow crash kernel dump process to be completed in a reasonable time which will also help in overall router recovery time.
How I did it
Setting loglevel attribute in crashkernel cmdline
How to verify it
Install SONiC image with crashkernel cmdline with loglevel set to warning and initiate an induced a crash (sysrq-trigger)
crashkernel boot and dump process will be completed in 20s-30s depending on the platform
dash doesn't support += operation to append to a variable's value. Use KDUMP_CMDLINE_APPEND="${KDUMP_CMDLINE_APPEND} " instead
The below error message is seen when a reboot is issued.
[ 342.439096] kdump-tools[13655]: /etc/init.d/kdump-tools: 117: /etc/default/kdump-tools: KDUMP_CMDLINE_APPEND+= panic=10 debug hpet=disable pcie_port=compat pci=nommconf sonic_platform=x86_64-accton_as7326_56x-r0: not found
#### Why I did it
If a process limits using nodes by mempolicy/cpusets, and those nodes become memory exhaustion status, one process may be killed by oom-killer.
No panic occurs in this case, because other node's memory may be free.
This means system total status may be not fatal yet.
#### How I did it
Remove 'vm.panic_on_oom=1' kernel flag from 'vmcore-sysctl.conf '
Create new file to "sysctl.d" with desired panic conditions.
It will trigger a vmcore dump using kdump-tools on these situations.
Signed-off-by: Shlomi Bitton <shlomibi@nvidia.com>
The default /etc/default/kdump-tools file provided by the kdump-tools
package doesn't set a value for KDUMP_CMDLINE_APPEND.
The default kdump command line arguments need to be set in order
to extend them to use additional arguments required for SONiC
platforms.
Signed-off-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>
- Allow platform specific reboot script to be called after crash kernel has
finished copying the kernel vmcore
- Disable pcie advanced features when running crash kernel. This improves
reliability of the crash kernel to successfully create a vmcore and also
reboot
- Allow crash kernel to reboot if a panic is seen while it is generating a
vmcore
- Fix crash kernel to use the SONiC specific /usr/local/bin/reboot script
instead of the Linux reboot command /sbin/reboot
- Use sonic_platform as the kernel command line parameter to pass platform identifier string
Signed-off-by: Rajendra Dendukuri <rajendra.dendukuri@broadcom.com>
