Commit Graph

7 Commits

Author SHA1 Message Date
Coiby Xu
a1c63fa644 add man documentation for kdumpctl get-default-crashkernel
A few typos and grammar issues are fixed as well.

Philipp Rudo <prudo@redhat.com>

Signed-off-by: Coiby Xu <coxu@redhat.com>
2022-04-24 09:35:05 +08:00
Coiby Xu
140da74a34 rewrite reset_crashkernel to support fadump and to used by RPM scriptlet
Rewrite kdumpctl reset-crashkernel KERNEL_PATH as
kdumpctl reset-crashkernel [--fadump=[on|off|nocma]]  [--kernel=path_to_kernel] [--reboot]

This interface would reset a specific kernel to the default crashkernel value
given the kernel path. And it also supports grubby's syntax so there are the
following special cases,
 - if --kernel not specified,
    - use KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump
    - otherwise use current running kernel, i.e. `uname -r`
 - if --kernel=DEFAULT, the default boot kernel is chosen
 - if --kernel=ALL, all kernels would have its crashkernel reset to the
   default value and the /etc/default/grub is updated as well

--fadump=[on|off|nocma] toggles fadump on/off for the kernel provided
in KERNEL_PATH. If --fadump is omitted, the dump mode is determined by
parsing the kernel command line for the kernel(s) to update.

CoreOS/Atomic/Silverblue needs to be treated as a special case because,
 - "rpm-ostree kargs" is used to manage kernel command line parameters
    so --kernel doesn't make sense and there is no need to find current
    running kernel
 - "rpm-ostree kargs" itself would prompt the user to reboot the system
   after modify the kernel command line parameter
 - POWER is not supported so we can assume the dump mode is always kdump

This interface will also be called by kexec-tools RPM scriptlets [1]
to reset crashkernel.

Note the support of crashkenrel.default is dropped.

[1] https://docs.fedoraproject.org/en-US/packaging-guidelines/Scriptlets/

Reviewed-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
2022-01-05 09:40:24 +08:00
Kairui Song
86130ec10f kdumpctl: Add kdumpctl reset-crashkernel
In newer kernel, crashkernel.default will contain the default
crashkernel value of a kernel build. So introduce a new sub command
to help user reset kernel crashkernel size to the default value.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
2021-07-08 15:18:45 +08:00
Kairui Song
e9e6a2c745 kdumpctl: Add kdumpctl estimate
Add a rough esitimation support, currently, following memory usage are
checked by this sub command:

- System RAM
- Kdump Initramfs size
- Kdump Kernel image size
- Kdump Kernel module size
- Kdump userspace user and other runtime allocated memory (currently
  simply using a fixed value: 64M)
- LUKS encryption memory usage

The output of kdumpctl estimate looks like this:
  # kdumpctl estimate
  Reserved crashkernel:    256M
  Recommanded crashkernel: 160M

  Kernel image size:   47M
  Kernel modules size: 12M
  Initramfs size:      19M
  Runtime reservation: 64M
  Large modules:
      xfs: 1892352
      nouveau: 2318336

And if the kdump target is encrypted:
  # kdumpctl estimate
  Encrypted kdump target requires extra memory, assuming using the keyslot with minimun memory requirement

  Reserved crashkernel:    256M
  Recommanded crashkernel: 655M

  Kernel image size:   47M
  Kernel modules size: 12M
  Initramfs size:      19M
  Runtime reservation: 64M
  LUKS required size:  512M
  Large modules:
      xfs: 1892352
      nouveau: 2318336
  WARNING: Current crashkernel size is lower than recommanded size 655M.

The "Recommanded" value is calculated based on memory usages mentioned
above, and will be adjusted accodingly to be no less than the value provided
by kdump_get_arch_recommend_size.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
2021-05-19 15:27:43 +08:00
Kairui Song
a53be67929 Update man page for new kdumpctl command: reload / rebuild
These two command are not documented, update the man page to let user
know how to use them.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2019-04-05 02:02:58 +08:00
Pingfan Liu
1a6cb43a19 kdumpctl: add showmem cmd
port from rhel, original patch is contributed by Minfei Huang:

Using /sys to determines crashkernel actual size is confusing since
there is no unit of measure.

Add a new command "kdumpctl showmem" to show the reserved memory kindly.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Signed-off-by: Minfei Huang <mhuang@redhat.com>
Acked-by: Bhupesh Sharma <bhsharma@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2018-05-21 14:06:30 +08:00
Dangyi Liu
37dc7c286c kdumpctl: Add man page for kdumpctl
kdumpctl is useful sometimes when users want to debug or setup ssh key
authentication. So add a man page for it.

Signed-off-by: Dangyi Liu <dliu@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Pratyush Anand <panand@redhat.com>
2015-08-19 14:15:34 +08:00