Package: kdump-tools Version: 1:1.5.9-7 Severity: normal I found that with the default line is kdump-tools.default
GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=384-:128M" running dmesg | grep -i crash does not give anything back, suggesting no memory is reserved. Changing the line to GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=384M-2G:64M,2G-:128M" gives: [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-4.6.0-1-amd64 root=/dev/mapper/sonny-root ro quiet crashkernel=384M-2G:64M,2G-:128M [ 0.000000] Reserving 128MB of memory at 720MB for crashkernel (System RAM: 6051MB) [ 0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz-4.6.0-1-amd64 root=/dev/mapper/sonny-root ro quiet crashkernel=384M-2G:64M,2G-:128M confirming memory is now reserved. -- System Information: Debian Release: stretch/sid APT prefers unstable APT policy: (500, 'unstable'), (500, 'testing') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages kdump-tools depends on: ii bsdmainutils 9.0.10 ii debconf [debconf-2.0] 1.5.59 ii init-system-helpers 1.34 ii kexec-tools 1:2.0.10-2 ii makedumpfile 1:1.5.9-7 kdump-tools recommends no packages. kdump-tools suggests no packages. -- Configuration Files: /etc/default/grub.d/kdump-tools.default changed: GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=384M-2G:64M,2G-:128M" -- debconf information: * kdump-tools/use_kdump: true