Diskless boot always fail - error dracut - could not boot

Hi all. I am try to run diskless client, but always have error - "Could not boot" from dracut. I'm using PXE, tftp and nfs. client iso build using rsync. Tftp work properly. I think it's error in nfs.
My pxelinux.cfg/default :
default rhel7

label rhel7
kernel vmlinuz-3.10.0-693.el7.x86_64
append initrd=initramfs-3.10.0-693.el7.x86_64.img
root=nfs:10.0.0.1:/nodeboot rw

Show mount output :
$ showmount -e 10.0.0.1
Export list for 10.0.0.1:
/nodeboot 10.0.0.1/24

What a problem? What i'm doing wrong?
I configure all like in https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html-single/Storage_Administration_Guide/index.html#ch-disklesssystems
But always get error - "Could not boot".
Server OS rhel 7