Mnesia has no access to create table in disc macOs dev mode

[shahryarjb]

Hello, I have read many posts about disc problem in the forum, but I have still this problem:

I have no problem to create ram copy

 {:create_table,
  {:aborted, {:bad_type, MishkaAuth.User.Users, :disc_copies, :nonode@nohost}}}}

I did this comment before creating a post:

Mnesia directory is not created when running iex -S mix and :mnesia.info() shows: Mnesia.nonode@nohost" is NOT used

create_schema must be called when mnesia is stopped. By adding mnesia to extra applications it is started automatically. When that happens it will create an in-memory schema. Some alternatives. create the mnesia schema before you start the application (create schema is a one-time operation so it could be done in a task like normal SQL schema migration. Check if the schema exist and if not stop mnesia, create the schema and start it as part of some startup logic. or perhaps add it to included_…

my config file:

config :mnesia, dir: "/Users/shahryar/Desktop/D-Access/mnesia_db"
# drwxr-xr-x   3 shahryar  staff         96 Mar 22 15:04 mnesia_db

My fields and mnesia name:

  @mnesia_tab __MODULE__

  @mnesia_tab_fields [
    :id,
    :full_name,
    :username,
    :email,
    :mobile,
    :password_hash,
    :unconfirmed_email,
    :unconfirmed_mobile,
    :roles,
    :scopes,
    :devices,
    :status,
    :inserted_at,
    :updated_at
  ]

And the function I create a disc_copies table

def start_mnesia() do
  :mnesia.stop()

  :mnesia.create_schema()
  |> IO.inspect(label: "Mnesia schema start of user ====>")

  :mnesia.start(:app)
  |> IO.inspect(label: "Application start of user ====>")


  case :mnesia.create_table(@mnesia_tab,
          type: :set,
          disc_copies: [Node.self()],
          attributes: @mnesia_tab_fields,
          index: [:username, :email, :mobile],
          record_name: @mnesia_tab,
          storage_properties: [ets: [{:read_concurrency, true}, {:write_concurrency, true}]]
        ) do
    {:atomic, :ok} -> :ok
    {:aborted, {:already_exists, @mnesia_tab}} -> :ok
    any -> {:error, {:create_table, any}}
  end
  |> IO.inspect(label: "Creating table ---->")

  :mnesia.wait_for_tables([@mnesia_tab], :timer.seconds(15))
  |> IO.inspect(label: "Mnesia wait for tables start of user ====>")
end

I am using mac os and dev mode with iex -S mix phx.server

Please help me to fix this issue, 3 or 4 years ago I fixed it, but I can not remember now

Thank you in advance

[shahryarjb]

I remove my custom path and it works, but I dont know why i can not set a dir for mnesia

for example if i set a path:

Application.put_env(:mnesia, :dir, "/Users/shahryar/Desktop/D-Access/mnesia_db")

or

:mnesia.stop()
Application.put_env(:mnesia, :dir, "/Users/shahryar/Desktop/D-Access/mnesia_db")

after that call

:mnesia..create_schema([node()])

It returns {:error, {:EXIT, :function_clause}}

I do not know why

Update

use this

Application.put_env(:mnesia, :dir, mnesia_dir |> to_charlist)

[rvirding]

@shahryarjb

use this

Application.put_env(:mnesia, :dir, mnesia_dir |> to_charlist)
```tool 

Yes, Mnesia is an old Erlang tool and in Erlang strings are charlists. That’s the way it is.

[shahryarjb]

Yes, Thank you, it is as you say sir. But I went through a very hard way to remember that more than 5 hours