Can't start postgres on linux

Question

When I run sudo -u postgres psql it gives error as

psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

So I check status by pg_lsclusters ,it gives status as down

So I tried to start the cluster by sudo pg_ctlcluster 11 main start ,it gives error as

Job for postgresql@11-main.service failed because the service did not take 
the steps required by its unit configuration.
See "systemctl status postgresql@11-main.service" and "journalctl -xe" for 
details.

Then I check log by journalctl -xe ,it gives

-- Subject: Unit postgresql@11-main.service has begun start-up
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit postgresql@11-main.service has begun starting up.
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: Error: 
/usr/lib/postgresql/11/bin/pg_ctl /usr/lib/postgresql/11/bin/pg_ctl start -D 
/data/aqu
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
18:35:50.032 UTC [3622] LOG:  listening on IPv4 address "0.0.0.0", port 5432
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
18:35:50.032 UTC [3622] LOG:  listening on IPv6 address "::", port 5432
 May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
 18:35:50.033 UTC [3622] LOG:  listening on Unix socket 
 "/var/run/postgresql/.s.PGS
 May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
 18:35:50.090 UTC [3623] LOG:  database system shutdown was interrupted; 
 last known
 May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
18:35:50.140 UTC [3623] LOG:  database system was not properly shut down; 
automati
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
18:35:50.147 UTC [3623] LOG:  redo starts at 9D/44F48998
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
 18:35:53.483 UTC [3624] a2i@postgres FATAL:  the database system is 
 starting up
 May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 
 18:35:54.422 UTC [3625] a2i@postgres FATAL:  the database system is 

starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:35:55.461 UTC [3626] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:35:55.465 UTC [3627] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:35:57.713 UTC [3628] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:35:57.861 UTC [3623] LOG:  redo done at 9D/AFFFFF98
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:35:59.416 UTC [3629] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:03.493 UTC [3630] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql

@11-main[3617]: 2019-05-08 18:36:04.431 UTC [3631] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:05.471 UTC [3632] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:05.477 UTC [3633] a2i@postgres FATAL:  the database system is starting up
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:06.776 UTC [3623] PANIC:  could not write to file "pg_wal/xlogtemp.3623": No
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:06.959 UTC [3622] LOG:  startup process (PID 3623) was terminated by signal
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:06.959 UTC [3622] LOG:  aborting startup due to startup process failure
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:07.108 UTC [3622] LOG:  database system is shut down
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: pg_ctl: could not start server
May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: Examine the log output.
May 08 18:36:07 ip-10-0-1-87 systemd[1]: postgresql@11-main.service: Can't open PID file /var/run/postgresql/11-main.pid (yet?) after start: No such
May 08 18:36:07 ip-10-0-1-87 systemd[1]: postgresql@11-main.service: Failed with result 'protocol'.
May 08 18:36:07 ip-10-0-1-87 systemd[1]: Failed to start PostgreSQL Cluster 11-main.
-- Subject: Unit postgresql@11-main.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit postgresql@11-main.service has failed.
--
-- The result is RESULT.
May 08 18:36:07 ip-10-0-1-87 sudo[3612]: pam_unix(sudo:session): session closed for user root

It may cause because of shutting down database improperly I don't need solution like taking dump of existing database and reinstall postgres and restore it..I have big data , it will take much. What will be the soultion to sort this?

Answer 1

It says in the logs what the problem is:

May 08 18:36:07 ip-10-0-1-87 postgresql@11-main[3617]: 2019-05-08 18:36:06.776 UTC [3623] PANIC:  could not write to file "pg_wal/xlogtemp.3623": No

I can't see what comes after "No" because it looks like you cut off that part of the message.

However, the database server is unable to write to the transaction logs directory and is quite sensibly refusing to continue. Stop what you are doing, take a complete backup of all the files in your data directory and below and then and only then figure out what the problem is.

You don't know what you are doing (or you wouldn't be posting here without reading the error log) and there is a good chance that anything else you do will make the situation worse.

Obvious things to check:

• Has the machine crashed recently?
• Have you run out of disk space?
• Have permissions on the directories been changed?

Answer 2

对我来说，这是通过更改bin目录的权限来解决的。

chmod 755 /bin