kdump missing /dev/disk/by-id causes lvm filter to fail
In the normal kernel we use the following filter
filter = [ "a|/dev/disk/by-id/scsi-3600508b1001c54e819425b728a0ca446-part2$|", "a|/dev/mapper/mpath.*|", "r/.*/" ]
When we try to panic the system we find that the kdump kernel is missing /dev/disk so the lvm filter doesn't work. This means that kdump cannot mount /var/crash
mount: mount /dev/mapper/vg_root-lv_kdump on /mnt failed: No such file or directory
dropping to initramfs
/ # lvm pvs -a
/ # ls /dev/disk
ls: /dev/disk: No such file or directory
/ # /sbin/udevd
bash: can't execute '/sbin/udevd': No such file or directory
We can't think of another way to define the lvm filter, and yet we can't get kdump to work with it the way it is.
How do we get udev working in the kdump kernel?