Postgresql-Server won't start after moving data directory

I am running a local postgresql server (9.5 & 9.6) on my Ubuntu 17.04 machine. After moving my data directories to another hard drive following this guide the server can't start.

I.e. with

sudo service postgresql restart && sudo service postgresql status 

● postgresql.service - PostgreSQL RDBMS
   Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled)
   Active: active (exited) since Mon 2017-11-06 10:31:32 CET; 1min 42s ago
  Process: 8962 ExecStart=/bin/true (code=exited, status=0/SUCCESS)
 Main PID: 8962 (code=exited, status=0/SUCCESS)

Nov 06 10:31:32 HERCULES systemd[1]: Starting PostgreSQL RDBMS...
Nov 06 10:31:32 HERCULES systemd[1]: Started PostgreSQL RDBMS.

The logs for both versions then contain the following:

pg_ctl: could not access directory "/media/daveknave/BIGFS/PGSQL/9.5/main": Keine Berechtigung

"Keine Berechtigung" translates to "Permission denied".

ls -l /media/daveknave/BIGFS/PGSQL/9.5/main

gives

```
drwxrwxrwx 5 postgres postgres 4096 Sep 25 21:42 base
drwxrwxrwx 2 postgres postgres 4096 Nov 3 21:07 global
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_clog
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_commit_ts
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_dynshmem
drwxrwxrwx 4 postgres postgres 4096 Sep 25 21:42 pg_logical
drwxrwxrwx 4 postgres postgres 4096 Sep 25 21:42 pg_multixact
drwxrwxrwx 2 postgres postgres 4096 Nov 3 21:07 pg_notify
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_replslot
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_serial
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_snapshots
drwxrwxrwx 2 postgres postgres 4096 Nov 3 21:07 pg_stat
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_stat_tmp
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_subtrans
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_tblspc
drwxrwxrwx 2 postgres postgres 4096 Sep 25 21:42 pg_twophase
-rwxrwxrwx 1 postgres postgres 4 Sep 25 21:

Verify the permissions on /main with

ls -l /media/daveknave/BIGFS/PGSQL/9.5/

Does postgres still have access to main?

Switch user to postgres with su - postgres and then navigate through the directory structure /media/daveknave/BIGFS/PGSQL/9.5/main/. Can you navigate past main into base?

Verify the file permissions beneath ..../base with the following comamnds:

ls -lR /media/daveknave/BIGFS/PGSQL/9.5/main/base > ~/postrgres_main_perm.log

and then

vi ~/postrgres_main_perm.log

If you find that the permissions are not correct in the log file, then run the following command to grant postgres all permissions to the directory ...main/base and all underlying sub-directories:

chown -Rv postgres:postgres /media/daveknave/BIGFS/PGSQL/9.5/main/base/

Caution:

Before you modify all permissions ensure the command works by replacing chown -Rv with something less destructive like ls -R or navigate down to the .../main directory and issue the shorter command: chown -Rv postgres:postgres base/. This will ensure you are applying the command to the correct directory.

Try restarting your PostgreSQL instance again.

StackExchange Database Administrators Q#190191, answer score: 7