fdisk: cannot open /dev/diskname: No such file or directory
I want to create partiton disk with 1GB but error showing...what is the reson for this?
Are you following along with a tutorial?
You have to substitute "diskname" for the actual disk you want to work with.
Like FabioReis said, post a picture of lsblk and show us the output.
There is no such things as this: /dev/diskname
What you'll need to use is something that looks like: /dev/sdb, /dev/vbc, /dev/nvme0n1
As the others have said, the output from lsblk would really help.