I modified the sshd_config but the ssh service became unavailable. How do I reset the config?
Here is the log:
Jul 29 14:10:03 bye sshd[578]: /etc/ssh/sshd_config line 6: Badly formatted port number.
Jul 29 14:10:03 bye systemd[1]: ssh.service: main process exited, code=exited, status=255/n/a
Jul 29 14:10:03 bye systemd[1]: Unit ssh.service entered failed state.
Jul 29 14:10:04 bye systemd[1]: ssh.service holdoff time over, scheduling restart.
Jul 29 14:10:04 bye systemd[1]: Stopping OpenBSD Secure Shell server...
Jul 29 14:10:04 bye systemd[1]: Starting Google Compute Engine VM initialization...
Jul 29 14:10:04 bye systemd[1]: Started Google Compute Engine VM initialization.
Jul 29 14:10:04 bye systemd[1]: Starting OpenBSD Secure Shell server...
Jul 29 14:10:04 bye systemd[1]: Started OpenBSD Secure Shell server.
Jul 29 14:10:04 bye sshd[582]: /etc/ssh/sshd_config line 6: Badly formatted port number.
Jul 29 14:10:04 bye systemd[1]: ssh.service: main process exited, code=exited, status=255/n/a
Jul 29 14:10:04 bye systemd[1]: Unit ssh.service entered failed state.
Jul 29 14:10:04 bye systemd[1]: ssh.service holdoff time over, scheduling restart.
Since you don't have access to your instance and you need to modify the sshd_config file you can either:
Delete the instance keeping the boot disk, attach it to another instance as secondary, modify the sshd_config file, detach the disk and then create a new instance using that disk.
Or you can modify the sshd_config file using the following startup-script:
#!/bin/bash
/bin/sed -i.bak 's/^Port .*/Port 22/g' /etc/ssh/sshd_config
This startup-script will modify the line that starts with "Port" to "Port 22". Also it will create a backup at /etc/ssh/sshd_config.bak.
After updating the instance metadata with the startup-script you need to reboot the instance because startup-scripts are executed when the instances boot up. Once you gain access to the instance, remove the script in order to avoid executing it to no avail.
I hope it helps.
Related
I installed mysql in my server. But it failed to start.
The error shows here:
the systemctl status mysqld.service info:
[root#localhost run]# systemctl status mysqld.service
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: failed (Result: start-limit) since Sat 2021-05-29 10:47:55 CST; 35s ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 256566 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=217/USER)
May 29 10:47:55 localhost.localdomain systemd[1]: Failed to start MySQL Server.
May 29 10:47:55 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
May 29 10:47:55 localhost.localdomain systemd[1]: mysqld.service failed.
May 29 10:47:55 localhost.localdomain systemd[1]: mysqld.service holdoff time over, sche...t.
May 29 10:47:55 localhost.localdomain systemd[1]: Stopped MySQL Server.
May 29 10:47:55 localhost.localdomain systemd[1]: start request repeated too quickly for...ce
May 29 10:47:55 localhost.localdomain systemd[1]: Failed to start MySQL Server.
May 29 10:47:55 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
May 29 10:47:55 localhost.localdomain systemd[1]: mysqld.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
thejournalctl -xeinfo:
May 29 10:48:00 localhost.localdomain postfix/master[21438]: warning: process /usr/libexec/postfix/pickup pid 257074 exit status 127
May 29 10:48:00 localhost.localdomain postfix/master[21438]: warning: /usr/libexec/postfix/pickup: bad command startup -- throttling
May 29 10:49:00 localhost.localdomain postfix/master[21438]: warning: process /usr/libexec/postfix/pickup pid 263057 exit status 127
May 29 10:49:00 localhost.localdomain postfix/master[21438]: warning: /usr/libexec/postfix/pickup: bad command startup -- throttling
May 29 10:50:00 localhost.localdomain postfix/master[21438]: warning: process /usr/libexec/postfix/pickup pid 269083 exit status 127
May 29 10:50:00 localhost.localdomain postfix/master[21438]: warning: /usr/libexec/postfix/pickup: bad command startup -- throttling
May 29 10:50:01 localhost.localdomain systemd[1]: Started Session 2986 of user root.
-- Subject: Unit session-2986.scope has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit session-2986.scope has finished starting up.
--
-- The start-up result is done.
I tried to run chown -R mysql:mysql /var/lib/mysql, It shows like this:
chown: invalid user: ‘mysql:mysql’
How can I start mysql?
You can fix this in few steps
Execute this command to check if mysql user exists: cat /etc/passwd | grep mysql
Validate if you have mysql in this file. It should look something like : mysql:x:27:27:MySQL Server:/var/lib/mysql:/bin/false
If mysql user is not present please create that user like this : useradd -d /var/lib/mysql mysql
If mysql user is present then make sure mysql user home path in /etc/passwd file actually exists and owned by mysql user (in the above case I mentioned /var/lib/mysql is home path and it has to be owned by mysql user)
Note: from what ever you have mentioned it looked like mysql user doesn't exist in your system. So it looks like creating the user with home path as /var/lib/mysql should solve the problem.
When i try to start mysql with:
service mysql start
/etc/init.d/mysql start
Then it takes a while and this shows:
[....] Starting mysql (via systemctl): mysql.serviceJob for mariadb.service failed because a timeout was exceeded.
See "systemctl status mariadb.service" and "journalctl -xe" for details.
failed!
Now when I go to journalctl -xe it shows:
Feb 18 14:54:43 mail systemd[1]: mariadb.service: Start operation timed out. Terminating.
Feb 18 14:55:24 mail systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
Feb 18 14:55:24 mail systemd[1]: Failed to start MariaDB 10.1.37 database server.
Feb 18 14:56:14 mail mysqld[8490]: 2019-02-18 14:56:14 140312205868416 [Note] /usr/sbin/mysqld (mysqld 10.1.37-MariaDB-0+deb9u1) starting as process 8490 ...
Feb 18 14:57:44 mail systemd[1]: mariadb.service: Start operation timed out. Terminating.
Feb 18 14:58:25 mail systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
Feb 18 14:58:25 mail systemd[1]: Failed to start MariaDB 10.1.37 database server.
I cant login anymore in root user. Then I start mysql in safemode and change the password.
this error mostly come when you moved from mysql to mariadb. here is the solution you need to run three commands and your application will start working again.
echo "/usr/sbin/mysqld { }" > /etc/apparmor.d/usr.sbin.mysqld
apparmor_parser -v -R /etc/apparmor.d/usr.sbin.mysqld systemctl
restart mariadb
I restarted MySQL server in one of the nodes in Percona Cluster.
Since the restart took much time, I interrupted the process. I tried restarting the MySQL server again. I got the following error:
Stale sst_in_progress file in datadir
I followed this link, https://www.percona.com/forums/questions-discussions/percona-xtradb-cluster/46846-sql-cluster-issue-need-help-please, and deleted the sst_in_progress file as mentioned in it.
Now, when I try restarting the MySQL server, I am getting this:
● mysql.service - LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon
Loaded: loaded (/etc/init.d/mysql; bad; vendor preset: enabled)
Active: failed (Result: exit-code) since Wed 2018-03-14 11:04:07 IST; 16min ago
Docs: man:systemd-sysv-generator(8)
Process: 23568 ExecStart=/etc/init.d/mysql start (code=exited, status=1/FAILURE)
Mar 14 11:04:00 systemd[1]: Starting LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon...
Mar 14 11:04:00 mysql[23568]: * Starting MySQL (Percona XtraDB Cluster) database server mysqld
Mar 14 11:04:00 /etc/init.d/mysql[23614]: MySQL PID not found, pid_file detected/guessed: /var/run/mysqld/mysqld.pid
Mar 14 11:04:07 mysql[23568]: * The server quit without updating PID file (/var/run/mysqld/mysqld.pid).
Mar 14 11:04:07 mysql[23568]: ...fail!
Mar 14 11:04:07 systemd[1]: mysql.service: Control process exited, code=exited status=1
Mar 14 11:04:07 systemd[1]: Failed to start LSB: Start and stop the mysql (Percona XtraDB Cluster) daemon.
Mar 14 11:04:07 systemd[1]: mysql.service: Unit entered failed state.
Mar 14 11:04:07 systemd[1]: mysql.service: Failed with result 'exit-code'.
One more thing is that no log is getting written to mysql-error.log file during restart because of which I am not able to continue debugging.
The best solution here, without being able to see more information, is to simply rm -rf $datadir and start the node back up. It will indeed SST which, depending on the dataset, will take a while. Estimate 1 hour for every 100GB of data over gigE.
If joiner node taking too much time so you can increase gcache.size upto 1 GB then restart joiner node, so if data is already there on new node so it will choose IST instead of SST.
set in my.cnf
wsrep_provider_options="gcache.size=1G"
For a particular project I wanted to have Mint (Sonja) appliance with all MariaDB and only MariaDB doing MySQL's work, without a hint of MySQL so I know I'm working with MariaDB.
The appliance is one where I've installed multiple open source projects that power their own website (Alfresco, Request Tracker, SuiteCRM, etc.), and all of them seem to have worked either with MariaDB, or just used Postgres without interesting difficulty, and up until I tried to create a new MariaDB database to add a clone of a specific Wordpress site, MariaDB worked predictably well with no headaches on the same system. Until now, where I can't seem to find a pulse.
The MariaDB troubleshooting page confirmed what I'd found in my investigations (in particular, a ps wwaux | grep mysql only turned up the grep process). The basic problem as I'd encountered it was when I tried to log in to create a database:
monk#toolchest ~ $ mysql -uroot -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket
'/var/run/mysqld/mysqld.sock' (2 "No such file or directory")
I've never gotten involved with MySQL's or MariaDB's /etc configuration files, but I looked briefly. They appeared sane to my uneducated eye.
Neither an aptitude reinstall mariadb-server nor a service mysql start produce any changes so far as I could tell.
For service mysql start, I got:
# service mysql start
Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.
The details for systemctl status mysql.service were:
● mysql.service - LSB: Start and stop the mysql database server daemon
Loaded: loaded (/etc/init.d/mysql; bad; vendor preset: enabled)
Active: failed (Result: exit-code) since Fri 2017-07-14 18:16:38 EEST; 1min 11s ago
Docs: man:systemd-sysv-generator(8)
Process: 5011 ExecStart=/etc/init.d/mysql start (code=exited, status=1/FAILURE)
Jul 14 18:16:38 toolchest /etc/init.d/mysql[5479]: 0 processes alive and '/usr/bin/mysql
Jul 14 18:16:38 toolchest /etc/init.d/mysql[5479]: [61B blob data]
Jul 14 18:16:38 toolchest /etc/init.d/mysql[5479]: error: 'Can't connect to local MySQL
Jul 14 18:16:38 toolchest /etc/init.d/mysql[5479]: Check that mysqld is running and that
Jul 14 18:16:38 toolchest /etc/init.d/mysql[5479]:
Jul 14 18:16:38 toolchest mysql[5011]: ...fail!
Jul 14 18:16:38 toolchest systemd[1]: mysql.service: Control process exited, code=exited
Jul 14 18:16:38 toolchest systemd[1]: Failed to start LSB: Start and stop the mysql data
Jul 14 18:16:38 toolchest systemd[1]: mysql.service: Unit entered failed state.
Jul 14 18:16:38 toolchest systemd[1]: mysql.service: Failed with result 'exit-code'.
The recent (i.e. non-cronned) content of journalctl -xe ran:
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysql.service has failed.
--
-- The result is failed.
Jul 14 18:16:38 toolchest systemd[1]: mysql.service: Unit entered failed state.
Jul 14 18:16:38 toolchest systemd[1]: mysql.service: Failed with result 'exit-code'.
/etc/mysql/mariadb.cnf and /etc/mysql/my.cnf both read (comments stripped):
[client-server]
!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mariadb.conf.d/
/etc/mysql/my.cnf.fallback dropps the latter !includedir. Commenting out the latter /etc/mysql/my.cnf to match the fallback file produced identical results.
I can edit my question to include more of /etc/mysql/*, but I wanted to ask. Error messages similar to the ERROR 2002 are to be found in questions like Can't connect to local MySQL server through socket '/var/mysql/mysql.sock' (38), but these appear to be MySQL rather than MariaDB, and I suspect this may be a MariaDB-specific fluke.
So I've been working on a rails server with MySQL and suddenly can't access my database. When I try to log in with mysql -u root -p I get ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2). I've read most of the forums I can find and looked through all the logs trying to reset mysqld.sock. I've tried reinstalling and repackaging unsuccessfully. The weird thing is that var/run/mysqld/ doesn't even exist after reinstalling.
So I decided to just back up my databases and overhaul everything. I cleaned out both apache and mysql with apt-get remove --purge and reinstalled. All went fine, apache launched fine, and then tried to relaunch mysql with systemctl start mysql which gave a prompt to check the log which says:
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: inactive (dead) (Result: exit-code) since Fri 2016-12-16 23:56:19 UTC; 17s ago
Process: 15690 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=1/FAILURE)
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: mysql.service: Control process exited, code=exited status=1
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: Failed to start MySQL Community Server.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: mysql.service: Unit entered failed state.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: mysql.service: Failed with result 'exit-code'.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: Stopped MySQL Community Server.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: mysql.service: Start request repeated too quickly.
Dec 16 23:56:19 ip-172-31-0-55 systemd[1]: Failed to start MySQL Community Server.
Update - I created the folder mysqld, which seems to allow sudo mysqld --initialize to run. Unfortunately this yielded the error
2016-12-17T00:16:36.298825Z 0 [ERROR] Can't change data directory owner to mysql
2016-12-17T00:16:36.299212Z 0 [ERROR] Aborting
So no party yet. Any thoughts would be hugely appreciated.
edit /etc/mysql/conf.d/mysql.cnf :
sudo nano /etc/mysql/conf.d/mysql.cnf
add this line :
socket=/var/run/mysqld/mysqld.sock
then restart mysql service :
sudo service mysql restart