How to reset mysql to factory settings? - mysql

So I dropped all the users in mysql.user and restarted the mysql database. Now I can't seem to get into the mysql again or how to reset it as if it was a clean install. I tried uninstalling it with brew uninstall mariadb and then reinstalling it with brew install mariadb, but that didn't fix it. The only resources I can find is about how to restore a user from inside mysql (which I am struggling to get into) or how to delete mysql completely by deleting files in certain directories (which don't exist in the first place).

There are two methods:
method 1:
1.Uninstall the mysql database, delete the data files in the /data directory, and then reinstall
Method 2:
1.Stop the mysql service (systemctl stop mysqld)
2.Delete the files in the /data directory (rm -fr /data/*)
3.Initialize mysql (mysqld --defaults-file=/mysql/my.cnf --initialize --user=mysql --basedir=/mysql/app/mysql --datadir=/mysql/data/3306/data/)
PS1: The path may be different from yours, you need to change it according to your own data directory

I did end up finding a solution to my problem. I didn't end up getting it from one source, but more cobbled a bunch of different stuff together until I figured out that this worked.
Stop the server: `brew services stop mariadb
Start it with this command: mysql --skip-grant-tables
Run this command to fix the table with no users: mysql_upgrade --force
Force kill mysql: ps -ef | grep mysql followed by kill -9 <pid>
Start up the server again: brew services start mariadb
I did first try mysql_install_db instead of mysql_upgrade --force as some site suggested, but that didn't work since mysql.user table still existed. It was just empty.

Related

Recreate a `mysql.user` table in mysql

I found my mysql.user table is messed up and use drop table if exists mysql.user to drop it, how can I create this special table manually and add my new account to it.
NB I have never tried this so I have no idea if it will work at all. YOU HAVE BEEN WARNED!!
Before you do anything, shut down the MySQL service and take a backup of the data folder (copy it elsewhere).
Next, either try creating a new data directory and run mysql_install_db (from the MySQL install directory, scripts/mysql_install_db --datadir=<new data directory>), or use a virtual machine and do the same. Whatever you do, do NOT install into the original folder. Use the same version of MySQL to do this
Whichever method you use, take the resultant files from <mysql data folder>/data (they should be called user.MYD, user MYI and user.frm) and copy them into your broken folder. Ensure that user rights are the same as the rest of the folder (owner and group should be read/write).
Restart your MySQL service and see if you can get into the system (no login information will be required, but you will have to log in to MySQL as root. If you can, recreate the relevant users for application access. If not, you still have a backup of the data folder.
In the event that it doesn't work, and assuming that you have recent backups, re-create the data folder completely using mysql_install_db (ensuring that you still have the copy of the folder you took before you started out), create the users, then restore your individual databases one by one from your last good backup. Do not restore the mysql database and tables - they will be built as you restore the other databases.
Try all this out on a virtual machine first - it'll help you find any problems along the way
Good luck
Thanks to #DaveyBoy 's answer. I operated like below on ubuntu 16.04, mysql 5.7.20, and got mysql.user table back:
sudo mysqld --initialize --datadir=~/data_tmp
sudo cp ~/data_tmp/mysql/user.frm /var/lib/mysql/mysql
sudo cp ~/data_tmp/mysql/user.MYD /var/lib/mysql/mysql
sudo cp ~/data_tmp/mysql/user.MYI /var/lib/mysql/mysql
sudo chown mysql:mysql /var/lib/mysql/mysql/user.frm
sudo chown mysql:mysql /var/lib/mysql/mysql/user.MYD
sudo chown mysql:mysql /var/lib/mysql/mysql/user.MYI
In mysql cli select * from mysql.user, table mysql.user should show up now.

Mysql server on MAMP won't start

My Mysql server on MAMP won't start.
This is the error:
161224 00:15:00 mysqld_safe Logging to '/Applications/MAMP/logs/mysql_error_log.err'.
161224 00:15:00 mysqld_safe Starting mysqld daemon with databases from /Applications/MAMP/db/mysql56
161224 00:15:01 mysqld_safe mysqld from pid file /Applications/MAMP/tmp/mysql/mysql.pid ended
I already tried the following commands:
> ps aux | grep mysql
> lsof -i
> sudo killall -9 mysqld
But the server is still not working.
Help ?
Remove the files ib_logfileN (N being the number) from the MAMP/db/mysql56 folder.
Then restart MAMP.
Should Work!!
Edit: If the above step doesn't work completely, please remove the ibdata<n> file as well, based on the comments.
I am working on oS-X (Mac), I was wondering around and came to see this post which help me a lot.
Many readers are being able to solve this problem thanks to the amazing here are the step to fix it out--
This issue generally occur due to explicitly closing of MAMP serves.
Quit MAMP.
In the finder go to Applications/MAMP/db/mysql/
Delete the last log file (look for a file named ib_logfileN – being N the log number Eg-ib_logfile0 and ib_logfile1) we can see in below image.
Please back up these before you delete them.
Restart MAMP.
It Worked for me, hope will work for you too..
I killed the process mysqlid via Activity Monitor on MacOS and restarted MAMP and MySql run successfully.
Update: Even this solution works without restarting MAMP.
My MAMPs MySQL stopped working after a power failure, this worked for me:
Stop servers from terminal
cd /Applications/MAMP/bin
./stop.sh
Create my.cnf file in /Applications/MAMP/conf with the following:
[mysqld]
innodb_force_recovery = 1
Start MySQL from same terminal window.
./startMysql.sh
Stop MySQL once it has recovered (Check the log in /Applications/MAMP/logs/mysql_error_log.err).
./stopMysql.sh
Remove the lines from my.cnf, save and start the servers as usual from the MAMP app.
MAMP is so touchy. Here's what worked for me:
cd /Applications/MAMP
Move or rename: mv tmp tmp_OLD.
Recreate the folder and a subfolder:
mkdir tmp; mkdir tmp/mysql
Now start mysql from MAMP. I think it's possible the socket lock file (tmp/mysql/mysql.sock.lock) gets corrupted and needs to be regenerated.
In some cases it may possible that the MySQL is already running on 3306 port. So, you can change the port number with 3307.
P.S: If you are bound to use 3306 in that case I think you can stop existing MySql server and let MAMP to do it for you.
I tried everything but I don't know why I didn't find this solution yet.
Quit Mamp
Go To /Application/Mamp/tmp/mysql
Delete File mysql.sock.lock
Start Mamp Server and that's all
+1 if this answer is helpful :)

How do you start a MySQL server on linux?

Pretty simple question here. I just want a SQL database on my version of Kali linux so I can practice SQL.
I opened the command line and entered tried to start mysql and get an error.
> mysql -u root
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'
I also made sure it was already installed using apt-get.
What are the steps I need to take to be able to make a database with tables and data that I can query?
I don't know about Kali, but on Ubuntu it would be
$ sudo service mysql start
Once that command returns, the mysqld service has started, so you can use the mysql client to connect to it.
Of course, you also have to make sure you have the mysql-server package installed, not just mysql-client and mysql-common, and that you've initialized the database instance. Complete post-installation instructions can be found in the official documentation, but the short version is
Make sure the installer has created the mysql user account. This is the account that will "own" the server process once it starts.
Change to your data directory. (I used the installer's default of /var/lib/mysql; you can change this by editing my.cnf.)
As root, execute the server daemon with the --initialize switch. Check whereis to determine the correct path, then
$ sudo /path/to/mysqld --initialize --user=mysql
This command will twiddle itself for a while, then display an automatically-generated password and exit. Once the command returns, the database instance has been initialized and the system tables created. You can now start the database instance normally (using service start), then log in as the database user root (which is not the same as the system user root) using the password from above, then change your password, create a new database user, log in as that user, create a user database, and start creating tables.
Again, the official documentation is the place to look for this; if any of the instructions in the official documentation differ from my instructions, you should ignore me and follow the official documentation's instructions.
If sudo service mysql start doesn't work for you, please try running mysqld_safe and don't kill the process. Use another tab to check the status of mysql service. This should solve your mysqld.sock issue.
If it doesn't work out, then please edit your my.cnf file and add the following:
socket=/var/lib/mysql/mysql.sock
And the permissions,
sudo chmod -R 755 /var/lib/mysql/
Hopefully, this should do it.
On my version of kali (2022-rolling), even though it's installed as MySQL, it's run as mariadb. To start it is:
sudo /etc/init.d/mariadb start
Try this
sudo service mysql start

Can't connect to local MySQL server through socket homebrew

I recently tried installing MySQL with homebrew (brew install mysql) and when I try to run it I get the following error:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
There is no /tmp/mysql.sock nor a /var/lib/mysql.sock.
I've searched and haven't found any mysql.sock file.
How can I fix this?
When you got the server running via
mysql.server start
you should see the socket in /tmp/mysql.sock. However, the system seems to expect it in /var/mysql/mysql.sock. To fix this, you have to create a symlink in /var/mysql:
sudo mkdir /var/mysql
sudo ln -s /tmp/mysql.sock /var/mysql/mysql.sock
This solved it for me. Now my phpMyAdmin works happily with localhost and 127.0.0.1.
Credit goes to Henry
Warning, this will wipe your databases, take a backup if you wish to keep them
I had some directories left from another mysql(8.0) installation, that were not removed.
I solved this by doing the following:
First uninstall mysql
brew uninstall mysql#5.6
Delete the folders/files that were not removed
rm -rf /usr/local/var/mysql
rm /usr/local/etc/my.cnf
Reinstall mysql and link it
brew install mysql#5.6
brew link --force mysql#5.6
Enable and start the service
brew services start mysql#5.6
Looks like your mysql server is not started. I usually run the stop command and then start it again:
mysqld stop
mysql.server start
Same error, and this works for me.
Try to connect using "127.0.0.1" instead "localhost".
If you are able to see "mysql stopped" when you run below command;
brew services list
and if you are able to start mysql with below command;
mysql server start
this means; mysql is able to start manually, but it doesn't start automatically when the operating system is started. Adding mysql to services will fix this problem. To do so, you can run below command;
brew services start mysql
After that, you may restart your operating system and try connecting to mysql to see if it started automatically. I did the same and stop receiving below error;
ERROR 2002 (HY000): Can't connect to local MySQL server through socket
'/tmp/mysql.sock' (2)
I hope this helps.
The file /tmp/mysql.sock is probably a Named-Pipe, since it's in a temporary folder. A named pipe is a Special-File that never gets permanently stored.
If we make two programs, and we want one program to send a message to another program, we could create a text file. We have one program write something in the text file and the other program read what our other program wrote. That's what a pipe is, except it doesn't write the file to our computer hard disk, IE doesn't permanently store the file (like we do when we create a file and save it.)
A Socket is the exact same as a Pipe. The difference is that Sockets are usually used over a network -- between computers. A Socket sends information to another computer, or receives information from another computer. Both Pipes and Sockets use a temporary file to share so that they can 'communicate'.
It's difficult to discern which one MySql is using in this case. Doesn't matter though.
The command mysql.server start should get the 'server' (program) running its infinite loop that will create that special-file and wait for changes (listen for writes).
After that, a common issue might be that the MySql program doesn't have permission to create a file on your machine, so you might have to give it root privileges
sudo mysql.server start
Since I spent quite some time trying to solve this and always came back to this page when looking for this error, I'll leave my solution here hoping that somebody saves the time I've lost. Although in my case I am using mariadb rather than MySql, you might still be able to adapt this solution to your needs.
My problem
is the same, but my setup is a bit different (mariadb instead of mysql):
Installed mariadb with homebrew
$ brew install mariadb
Started the daemon
$ brew services start mariadb
Tried to connect and got the above mentioned error
$ mysql -uroot
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
My solution
find out which my.cnf files are used by mysql (as suggested in this comment):
$ mysql --verbose --help | grep my.cnf
/usr/local/etc/my.cnf ~/.my.cnf
order of preference, my.cnf, $MYSQL_TCP_PORT,
check where the Unix socket file is running (almost as described here):
$ netstat -ln | grep mariadb
.... /usr/local/mariadb/data/mariadb.sock
(you might want to grep mysql instead of mariadb)
Add the socket file you found to ~/.my.cnf (create the file if necessary)(assuming ~/.my.cnf was listed when running the mysql --verbose ...-command from above):
[client]
socket = /usr/local/mariadb/data/mariadb.sock
Restart your mariadb:
$ brew services restart mariadb
After this I could run mysql and got:
$ mysql -uroot
ERROR 1698 (28000): Access denied for user 'root'#'localhost'
So I run the command with superuser privileges instead and after entering my password I got:
$ sudo mysql -uroot
MariaDB [(none)]>
Notes:
I'm not quite sure about the groups where you have to add the socket, first I had it [client-server] but then I figured [client] should be enough. So I changed it and it still works.
When running mariadb_config | grep socket I get:
--socket [/tmp/mysql.sock]
which is a bit confusing since it seems that /usr/local/mariadb/data/mariadb.sock is the actual place (at least on my machine)
I wonder where I can configure the /usr/local/mariadb/data/mariadb.sock to actually be /tmp/mysql.sockso I can use the default settings instead of having to edit my .my.cnf (but I'm too tired now to figure that out...)
At some point I also did things mentioned in other answers before coming up with this.
After installing macos mojave, had to wipe mysql folder under /usr/local/var/mysql and then reinstall via brew install mysql otherwise permission related things would come up all over the place.
In my case, the culprit was found in the logfiles:
$ tail /usr/local/var/mysql/<hostname>.lan.err
2019-09-19 7:32:21 0 [ERROR] InnoDB: redo log file './ib_logfile0' exists. Creating system tablespace with existing redo log files is not recommended. Please delete all redo log files before creating new system tablespace.
2019-09-19 7:32:21 0 [ERROR] InnoDB: Database creation was aborted with error Generic error. You may need to delete the ibdata1 file before trying to start up again.
So I renamed ib_logfile0 to get rid of the error (I had to do the same with ib_logfile1 afterwards).
mv /usr/local/var/mysql/ib_logfile0 /usr/local/var/mysql/ib_logfile0_bak
mv /usr/local/var/mysql/ib_logfile1 /usr/local/var/mysql/ib_logfile1_bak
brew services restart mariadb
I got the same error and this is what helped me:
$ln -sfv /usr/local/opt/mysql/*.plist ~/Library/LaunchAgents
$launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
$mysql -uroot
mysql>
I faced the same problem on my mac and solved it, by following the following tutorials
https://mariadb.com/resources/blog/installing-mariadb-10116-mac-os-x-homebrew
But don't forget to kill or uninstall the old version before continuing.
Commands:
brew uninstall mariadb
xcode-select --install
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" - See more at: https://mariadb.com/resources/blog/installing-mariadb-10116-mac-os-x-homebrew#sthash.XQoxRoJp.dpuf
brew doctor
brew update
brew info mariadb
brew install mariadb
mysql_install_db
mysql.server start
Just to add to these answers, In my case I had no local mySQL server, it was running inside a docker container. So the socket file does not exist and will not be accessible for the "mysql" client.
The sock file gets created by mysqld and mysql uses this to communicate with it.
However if your mySql server is not running local, it does not require the sock file.
By specifying a host name/ip the sock file is not required e.g.
mysql --host=127.0.0.1 --port=3306 --user=xyz --password=xyz
If "mysqld" IS running, it's possible your data is corrupted. Try running this:
mysqld
Read through the wall of data, and check if mysqld is reporting that the database is corrupted. Corruption can present in many unintuitive ways:
mysql -uroot returns "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)".
mysql.server start returns "ERROR! The server quit without updating PID".
Sequel Pro and MySQL Workbench responds that they can't connect to MySQL on localhost or 127.0.0.1.
To recover your data, open my.cnf and add the following line in the [mysqld] section:
innodb_force_recovery=1
Restart mysqld:
$ brew services restart mysql#5.6
Now you can connect to it, but it’s in limited read-only mode.
If you're using InnoDB, run this to export all your data:
$ mysqldump -u root -p --all-databases --add-drop-database --add-drop-table > data-recovery.sql
The file is created in your ~ dir. It may take some time.
Once finished, remove innodb_force_recovery=1 from my.cnf, then restart mysql in normal mode:
$ brew services restart mysql#5.6
Drop all the databases. I did this using Sequel Pro. This deletes all your original data. Make sure your data-recovery.sql looks good before doing this. Also consider backing up /usr/local/var/mysql to be extra careful.
Then restore the databases, tables, and data with this:
$ mysql -uroot < ~/data-recovery.sql
This can be a long import/restoration process. Once complete, you’re good to go!
Thanks go to https://severalnines.com/database-blog/my-mysql-database-corrupted-what-do-i-do-now for the recovery instructions. The link has further instructions on MyISAM recovery.
You'll need to run mysql_install_db - easiest way is if you're in the install directory:
$ cd /usr/local/Cellar/mysql/<version>/
$ mysql_install_db
Alternatively, you can feed mysql_install_db a basedir parameter like the following:
$ mysql_install_db --basedir="$(brew --prefix mysql)"
After a restart I could not connect with the local mariadb, a search also brought me to this page and I wanted to share my solution with you.
I noticed that the directory my.cnf.d in /usr/local/etc/ is missing.
This is a known bug with homebrew that is described and solved there. https://github.com/Homebrew/homebrew-core/issues/36801
fast way to fix: mkdir /usr/local/etc/my.cnf.d
When running mysql_secure_installation and entering the new password I got:
Error: Can't connect to local MySQL server through socket
'/tmp/mysql.sock' (2)
I noticed when trying the following from this answer:
netstat -ln | grep mysql
It didn't return anything, and I took that to mean that there wasn't a .sock file.
So, I added the following to my my.cnf file (either in /etc/my.cnf or in my case, /usr/local/etc/my.cnf).
Under:
[mysqld]
socket=/tmp/mysql.sock
Under:
[client]
socket=/tmp/mysql.sock
This was based on this post.
Then stop/start mysql again and retried mysql_secure_installation which finally let me enter my new root password and continue with other setup preferences.
This works for me:
brew upgrade mysql
If brew does not complete "postinstall"
I only have to use:
sudo chown -R $(whoami) /usr/local/*
then completed postinstall by:
brew postinstall mysql#5.7
next step just start mysql#5.7 service.
It worked for me on MacOS Monterey.
I also ran into this... it seemingly resulted from some leftover artifacts of multiple mysql installs on my dev machine. Every time I attempted to start or restart the mysql service it would crash. Ultimately, working through the err file helped me solve my issue.
Setup:
M1 Macbook Pro running OS 12 (Monterey)
Homebrew install of mysql#5.7
At various points during troubleshooting I tried uninstalling everything mysql in my Homebrew list, deleting /opt/homebrew/var/mysql, and reinstalling mysql#5.7 to no avail. I also tried restarting my machine.
I was able to validate what was happening when the service failed to start by reviewing the err (e.g., MyComputerName.local.err) log that it was spitting out into /opt/homebrew/var/mysql/ when I tried to start/restart the service via Homebrew. In the beginning, I was seeing things like this that pointed to issues with the config:
mysqld: Table 'mysql.plugin' doesn't exist
TIMESTAMPZ 0 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
TIMESTAMPZ 0 [ERROR] unknown variable 'mysqlx-bind-address=127.0.0.1'
TIMESTAMPZ 0 [ERROR] Aborting
I deleted my.cnf and my.cnf.default in /opt/homebrew/etc and attempted to start the service again. Then, the failure changed to this:
TIMESTAMPZ 0 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist
TIMESTAMPZ 0 [ERROR] Fatal error: Failed to initialize ACL/grant/time zones structures or failed to remove temporary table files.
TIMESTAMPZ 0 [ERROR] Aborting
At this point I noticed several mysql lock files in /opt/homebrew/var/homebrew/locks/ (mysql.formula.lock, mysql.formula#5.7.lock, mysql.formula#8.0.lock); I deleted those files, as well as anything mysql in /opt/homebrew/var/homebrew/linked.
After that, I was able to start mysql without any issues.
just to complete this thread.
therefore MAMP (PRO) is used pretty often
the path here is
/Applications/MAMP/tmp/mysql/mysql.sock
I manually started mysql in the system preferences pane by initialising the database and then starting it. This solved my problem.
I had same problem. After trying all these methods without success I did the following:
tail -f the-mysql-or-maria-db-error-file.err
in another console:
brew services restart mariadb
I saw the following error:
"MAC HOMEBREW Crash recovery failed. Either correct the problem (if
it's, for example, out of memory error) and restart, or delete tc log
and start mysqld with"
So I changed the tc.log extesion to tc.log.txt and restart mariadb
brew services restart mariadb
and done!
[LINUX]
Though answer is expected to be for MacOS only but in Linux we may face the same Error.
I was facing the same issue in Linux. I ran this command:
sudo /etc/init.d/mysql.server start
and I was able to run the MySQL server
Ref. https://gist.github.com/vinodpandey/1a4b5b8228f9a000ca236820185fc3bc
I just ran into this problem, I did some tricks but for me it didn't work. If you used macOS, here is what I did. We start by uninstalling mysql and then reinstalling it.
brew uninstall mysql
brew install mysql
Note: you must have homebrew installed
This happened to me today 2023-02-23 after a homebrew update.
Homebrew had created a new my.cnf.default file, I backed up my old one and replaced it with this new default and restarted Mariadb and everything worked including the old root password.
For me, I had installed mariadb long time ago, then installed mysql#5.7.
When I executed mysql -uroot, I get the error:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
Reading the answers:
I uninstalled mariadb
Deleted the folder /usr/local/var/mysql
Ran the command mysqld --initialize
Then I was able to mysql -uroot -p

Create MySQL database in OS X Lion

I am trying to set up a dev environment on my Mac laptop, and I have run into some trouble when installing mysql. When I try to create a database, I get the following error:
ERROR 1006 (HY000): Can't create database 'SummerGypsy_development'
(errno: 2
From what I have gathered, this means there was some problem in creating the database on the disc.
Here is how I installed mysql:
First, using Homebrew, I executed:
brew install mysql
Once that finished, I tried running mysql_install_db, but got an error. To remedy this error, I ended up running
mysql_install_db --basedir=/usr/local/
I can run mysql, but creating a database does not work. I ran
mysqladmin variables | grep datadir
To find where mysql was trying to create the database. The output was: /usr/local/mysql/data
/usr/local/mysql and /usr/local/mysql/data directories do not actually exist, and I have a feeling that the datadir is pointing here because of the basedir I passed into mysql_install_db. As a quick fix, I tried creating both directories, and then running
chown -R mysql:mysql /usr/local/mysql
to give mysql permissions in this directory. This did not fix the problem, though.
Does anyone have any suggestions?
you need to change the permissions in the data.
chown -R mysql:mysql /usr/local/mysql/data
You might want to try installing from the .dmg file (installer, system preferences pane, and startup script) that is distributed directly from MySQL. There is a thread on Getting MySQL work on OSX 10.7 Lion that you might want to take a look at. These steps helped me get MySQL running on OSX Lion. Hope this helps.
I tried lot of the suggestions including the file permission reset with no luck. But i then restarted the mysql using the command "./mysqld_safe &" (excluding quotes) and it worked.