Check available kernels (Example: section):

/boot]# geninitrd 

Regenarete (adding -v to see details) as suggested in above examples:

/sbin/geninitrd -f --initrdfs=initramfs /boot/initrd-KERVER.gz KERVER

Getting shell just after initrd boot ends/fails: Edit /etc/sysconfig/system , set:

RUN_SULOGIN_ON_ERR=no

Add

debugrd=sh 

to kernel boot options (by editing /boot/grub/grub.cfg or adding to GRUB_CMDLINE_LINUX_DEFAULT in /etc/sysconfig/grub and running update-grub)

Reboot. HINT: CTRL+PgUp/PgDown scrolls initrd logs.