Marius, can you please have a look at this?
This is a known problem with the error messages produced by mkfs.xfs.
The name "lv-filesystem" is too long by one character. If you read the error message carefully, you can see that it does indeed tell you:
Invalid value lv-filesystem for -L option
/* label */ [-L label (maximum 12 characters)]
I have long hemmed and hawed about this. Should we code all the rules for valid names for all filesystem types into Cockpit? Should mkfs.xfs produce useful error messages?
I guess it's "all of the above". I'll make backlog item for Cockpit to do explicit pre-validation of filesystem labels.
Proposed fix: https://github.com/cockpit-project/cockpit/pull/10754
> The "Overwrite existing data with zeros" option works fine.
This option shouldn't make any difference, and I could reproduce the error message with both "Overwrite existing data with zeros" and "Don't overwrite existing data". The only thing that matters is the length of the "Name" field.
Can you confirm?