root user not permitted to create new folder

Hello,

How can I get the root user able to create directories?

root@Digi_CM_Device:/etc# cd /work
-bash: cd: /work/: No such file or directory

root@Digi_CM_Device:/# mkdir work
mkdir: Cannot create directory `work’: Operation not permitted

Model No. : Digi_CM_Device
Serial No. : V62437350
F/W Rev. : v1.9.5.3
B/L Ver. : v1.2.0

I have the same issue. Any solution to this?