The Problem

Unable to generate kdump and fails with the following error:

Checking for memory holes : [100.0 %] | copy_bitmap_file: Can't write the bitmap(/tmp/kdump_bitmapQijuck). No space left on device"
kdump: dump target is /dev/[ 14.793505] EXT4-fs (dm-0): re-mounted. Opts: (null)
mapper/VGExaDb-kdump_vol
kdump: saving to /kdumproot/kdump/u01/crashfiles/127.0.0.1-2020-04-29-09:46:31/
kdump: saving vmcore-dmesg.txt
kdump: saving vmcore-dmesg.txt complete
kdump: saving vmcore
The kernel version is not supported.
The makedumpfile operation may be incomplete.
Checking for memory holes : [100.0 %] | copy_bitmap_file: Can't write the bitmap(/tmp/kdump_bitmapQijuck). No space left on device
create_2nd_bitmap: Can't copy 1st-bitmap to 2nd-bitmap.

makedumpfile Failed.
kdump: saving vmcore failed
touch: cannot touch '/kdumproot/u01/crashfiles/kdump_post.log': No such file or directory
tee: /kdumproot/u01/crashfiles/kdump_post.log: No such file or directory
2020-04-29 09:46:38 +0200 [INFO] Started kdump post
tee: /kdumproot/u01/crashfiles/kdump_post.log: No such file or directory

The Solution

Kdump initramfs unable to fetch real disk in order to dump the core.

Due to huge memory system need some place for makedumpfile to work and mark included/excluded memory pages. Add –work-dir to the makedumpfile command which will use actual disk rather than kdump ramdisk.

1. Edit the /etc/kdump.conf file as below and add –work-dir=/kdumproot/kdump/u01/crashfiles entry.

# vi /etc/kdump.conf
core_collector makedumpfile -p -d 31 --work-dir=/kdumproot/kdump/u01/crashfiles

2. Restart kdump service:

# systemctl restart kdump

Note that path found for –work-dir came from below message:

kdump: saving to /kdumproot/kdump/u01/crashfiles/127.0.0.1-2020-04-29-09:46:31/