diff --git a/right-fit-swap-for-laptop-hibernation-Ubuntu-20.04-full-ZFS-install.md b/right-fit-swap-for-laptop-hibernation-Ubuntu-20.04-full-ZFS-install.md
index dd28767..96c0059 100644
--- a/right-fit-swap-for-laptop-hibernation-Ubuntu-20.04-full-ZFS-install.md
+++ b/right-fit-swap-for-laptop-hibernation-Ubuntu-20.04-full-ZFS-install.md
@@ -114,6 +114,13 @@ cryptsetup luksFormat --cipher aes-xts-plain64 --verify-passphrase --key-size 25
 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=/dev/mapper/cryptswap1"
 ~~~
 
+### to be solve
+
+~~~
+cryptsetup: ERROR: Couln't resolve device rpool/ROOT/ubuntu_...
+cryptsetup: WARNING: Couln't determine root device
+~~~
+
 ## xfce4-power-manager suspend to hibernate option
 
 source : [docs.xfce.org - Frequently Asked Questions - Xfce4 Power Manager](https://docs.xfce.org/xfce/xfce4-power-manager/faq)