Inspur OS, Installation Manual

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Figure 10-8 Adding the Boot Parameter
b. Make a backup and regenerate the grub file.
On BIOS-based server:
# grub2-mkconfig -o /boot/grub2/grub.cfg
On UEFI-based server:
# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
For the large ext4 file system (at TB level), the configuration of crashkernel=auto
is not reliable, and probably leads to the out-of-memory problem when the
dump kernel is enabled. Hence, you need to specify the reserved memory value
and manually trigger the kdump test to see whether it can generate the vmcore
file.
According to the following explanation of Red Hat, the reserved memory size
depends on the disk space used by the file system. For example, it needs to
reserve 512 MB of memory for a 2.1 TB ext4 file system and 1.88 GB of memory
for a 16 TB ext4 file system.
(Kdump fails with large ext4 file system because fsck.ext4 gets OOM-killed
https://access.redhat.com/solutions/692783)
2. Specify the dump target.
The dump directory is configured in /etc/kdump.conf , and the vmcore file is
dumped in /var/crash/ by default.
# vim /etc/kdump.conf