Cannot get authorization to run pg_dumpall

All I am trying to do is backup my existing database cluster in order to upgrade from Postgresql 9.4.8 to 9.5. I am on Ubuntu 16.04.

I am aware of this post: Postgres password authentication fails. In fact, it was already bookmarked from the last time I had this problem. I do not claim any meaningful postgres knowledge. I don't always get what is supposed to be a psql command and what is supposed to be a bash command, and the blogs and what not I've seen don't always make that clear to me. PG is just my backend for my Django projects. I certainly don't understand how I am having this problem again.

My Ubuntu user is malikarumi. I have two postgres users, maikarumi and postgres. Postgres is the superuser. I tried to make malikarumi a superuser as well some time ago but that apparently failed and no, I don't know why.

Here is my first attempt today:

malikarumi@Tetuoan2:~$ pg_dumpall > 9-4-backuppg_dumpall: query failed: ERROR:  permission denied for relation pg_authidpg_dumpall: query was: SELECT oid, rolname, rolsuper, rolinherit,rolcreaterole, rolcreatedb, rolcanlogin, rolconnlimit, rolpassword, rolvaliduntil, rolreplication, pg_catalog.shobj_description(oid, 'pg_authid') as rolcomment, rolname = current_user AS is_current_user FROM pg_authid ORDER BY 2

This came next:

malikarumi@Tetuoan2:~$ pg_dumpall > 9-4-backup -U postgresPassword: 

Note there nothing, no help, no indication what is wrong or what to do about it.

Password: Password: pg_dump: [archiver (db)] connection to database "esselldb" failed: FATAL:  password authentication failed for user "postgres"pg_dumpall: pg_dump failed on database "esselldb", exiting

Then I tried again with a blank password and a semicolon

malikarumi@Tetuoan2:~$ pg_dumpall > 9-4-backup -U postgres;Password: pg_dumpall: could not connect to database "template1": fe_sendauth: no password supplied

Note the password works for psql

malikarumi@Tetuoan2:~$ psql -U postgresPassword for user postgres: Note the password works with psqlpsql (9.4.8)Type "help" for help.

But the command does not, with or without the semicolon

postgres=# pg_dumpall > 9-4-backuppostgres-# pg_dumpall > 9-4-backup;ERROR:  syntax error at or near "pg_dumpall"LINE 1: pg_dumpall > 9-4-backup

This works

malikarumi@Tetuoan2:/etc/postgresql/9.4/main$ sudo cat pg_hba.conf[sudo] password for malikarumi: 

Apparently, this is the unix user, not the database user. But it is, and always has been, the same password.

I changed this

# Database administrative login by Unix domain socketlocal   all             postgres                                md5

to peer, as suggested in the prior post (again - how could it change back?!)

But I could not restart postgres

malikarumi@Tetuoan2:/etc/postgresql/9.4/main$ pg_ctl stoppg_ctl: command not foundmalikarumi@Tetuoan2:/etc/postgresql/9.4/main$ cd ~malikarumi@Tetuoan2:~$ pg_ctl stoppg_ctl: command not found

It did not work from psql either

postgres=# pg_ctl stoppostgres-# pg_ctl stop;ERROR:  syntax error at or near "pg_ctl"LINE 1: pg_ctl stop        ^postgres=# 

But at least psql still lets me in....

So I rebooted the whole machine and tried again. You know what happened

malikarumi@Tetuoan2:~$ pg_dumpall > 9-4-backup -U postgrespg_dumpall: could not connect to database "template1": FATAL:  Peer authentication failed for user "postgres"

So I did successfully change it, but I still can’t get it to work. NOTE: It did NOT ask me for my password!

Then I tried this

malikarumi@Tetuoan2:~$ su postgresPassword: the right onesu: Authentication failuremalikarumi@Tetuoan2:~$ su postgresPassword: a blank onesu: Authentication failure

And now you are up to date. BTW, I have been to the official postgres docs many times, and find them dense and barely comprehensible. If you also know of a good base tutorial for a non db person like me, that would be helpful. Thanks.