Content of dracut.conf
# additional kernel modules to the default
#add_drivers+="cciss"

#omit_drivers+="hpsa"
==================================================================

[root@localhost boot]# rpm -qlp kernel-lt-4.4.176-1.el7.elrepo.x86_64.rpm | grep cciss
/lib/modules/4.4.176-1.el7.elrepo.x86_64/kernel/drivers/block/cciss.ko
[root@localhost boot]# rpm -qlp kernel-lt-4.4.176-1.el7.elrepo.x86_64.rpm | grep hpsa
/lib/modules/4.4.176-1.el7.elrepo.x86_64/kernel/drivers/scsi/hpsa.ko

======================================================================
[root@localhost boot]# lsinitrd initramfs-4.4.176-1.el7.elrepo.x86_64.img | grep cciss
[root@localhost boot]# lsinitrd initramfs-4.4.176-1.el7.elrepo.x86_64.img | grep hpsa
-rwxr--r--   1 root     root       161320 Mar  4 02:22 usr/lib/modules/4.4.176-1.el7.elrepo.x86_64/kernel/drivers/scsi/hpsa.ko

=======================================================================

[root@localhost boot]# lsmod | grep cciss
[root@localhost boot]# lsmod | grep hpsa
hpsa                   98304  2
scsi_transport_sas     45056  1 hpsa


========================================================================
[root@localhost mapper]# ls -la centos-*
lrwxrwxrwx. 1 root root 7 Mar  4 02:51 centos-home -> ../dm-2
lrwxrwxrwx. 1 root root 7 Mar  4 02:51 centos-root -> ../dm-0
lrwxrwxrwx. 1 root root 7 Mar  4 02:51 centos-swap -> ../dm-1
[root@localhost mapper]# pwd
/dev/mapper