UPDATE: The sysadmin in my company deleted the /tmp directory and created a
symbolic link to a mounted drive (e.g. ln -s /mnt/somewhere /tmp).
MySQL apparently didn't like this symbolic link.
Once a real /tmp directory on the local filesystem was created the problem went away.
I'm running a process (rake db:migrate) which causes MySQL to try to create a temp file.
However, the following error is appearing:
Mysql::Error: Can't create/write to file '/tmp/#sql_196_0.MYI' (Errcode: 13):
SHOW FIELDS FROM `user_rules`
Errcode 13 apparently is a file permission issue.
The user that is running the process has write permissions to the /tmp directory.
I also searched the web, and someone mentioned that the issue could be the file be prefixed with a pound sign (e.g. '#").
I went to the /tmp directory and tried to create the file and noticed that in certain cases I can't create the file. So I'm wondering if indeed the pound sign is causing the problem. And if it is, how can use MySQL or Rails to fix the problem:
cd /tmp
echo "Hello" > #sql_123
touch #sql_123
echo "Hello" > "#sql_123"
touch "#sql_123"
The 2nd and 3rd commands (without quotes) are failing. The 4th and 5th lines (with quotes) are working. So maybe the failure is because of the pound sign not being in quotes or escaped with a backslash. But again, even if that is the cause, I'm not sure how to tell MySQL or Rails how to deal with it.
Any ideas?
In a shell you need quotes because # introduces a comment, unless escaped by a backslash or quotes. Those #sql_123 files with a prefix of a pound-sign are temporary files owned by mysql, they are normal. You cannot move them however and whenever they are present you cannot move your database using the binary files, you either need to shutdown and move; or do a mysqldump to SQL.
Now for your sysadmin, did he delete /tmp while mysql was running? Mysql opens files in /tmp and then deletes them from the directory leaving the file-handle open. You would see differences in disk space while the server is up or down. MySQL creates all temporary files as hidden files. This ensures that the temporary files are removed if mysqld is terminated. The disadvantage of using hidden files is that you do not see a big temporary file that fills up the file system in which the temporary file directory is located.
So if you would like to keep the symlink (i.e. to a larger disk) then you would better shutdown mysql, create the link, and then start mysql to find it has no problem with symlinks.
Related
Starting on PHP/MySQL Development and as the title states, downloaded MySQL 8.0.15 DMG. Installed. However, when I attempt to run the terminal command:
"sudo /usr/local/mysql/support-files/mysql.server.start"
I get:
"Starting MysQl .......... "
which finally ends in:
ERROR! The server quit without updating PID file (/usr/local/mysql/data/Macbook.hsd.comcast.net.pid)
So far I have tried:
Tried to remove the "Macbook.hsd.comcast.net.pid" file located in the data directory but all i keep getting a "No Such file or directory"
To look for default "my.cnf" file to mod or to add the default values, HOWEVER I read that: "By default the OS X installation does not use a my.cnf, and My SQL just uses the default values. To set up your own my.cnf, you could just create a file straight in /etc.
An "auto.cnf" exists in the data folder, i'm not sure if MySQL uses that or would respect a "my.cnf" created in the /usr/local/sql/data/ folder.
I'm not sure of the proper location to create a "my.cnf" (see, all I want to do is set the proper value for the "pid-file" such as pid-file = /var/run/mysqld/mysqld.pid and then create the directory and give it the proper permissions. SEE UPDATE AT BOTTOM:
I'm cannot access the "data" folder in MySQL folder (which is alias of): "/usr/local/mysql-8.0.15-macos10.14-x86_64/". It keeps telling me I don't have permission. There is a little red dot
I have set checked the permissions in "/user/local/mysql/" and did a
"sudo chown -RL root:mysql /user/local/mysql"
"sudo chown -RL _mysql:mysql /usr/local/mysql/data"
In the /mysql/ directory now everything reads:
Stumped and not sure where to move on from here.
Is the fact that I can't access the data folder a result because I haven't made one/specified one? Can't seem to find an answer for getting MySQL working with HighSierra/Mojave. I can't believe that it's just dead.
I would appreciate any/all help.
UPDATE/EDIT:
Was able to add my user permissions to the "/user/local/mysql/data" folder and was finally able to access the error file ("Macbook.hsd.comcast.net.err") and a "auto.cnf".
The "auto.cnf" file is empty besides a single line: [auto] server-uuid=e7986494-331d-11e9-9691-bec9b3249da6 (not sure if I need to modify the auto.cnf and add PID entries). See error BELOW which seems to indicate otherwise.
The Error file had repeated Errors (occurred several Times):
This doesn't seem far too specific, but somehow I cannot find anyone else with this problem (at least on stack and google). People have issues with errcode 2, but every thing I've seen is people having issues with mysql's tmp directory. I've tried changing that, and that's given no luck.
I've also made sure that the owner/group of the mysql "datadir" is mysql.
I'm assuming the cause of this is because I have recently moved the mysql datadir to my /ssd directory.
I have changed the datadir location after copying /var/lib/mysql to /ssd and have restarted mysql.
For /var/lib/mysql, I renamed the mysql folder to mysql-old, as that folder was no longer in use. Just in case, I created a symlink in place of it that points to the /ssd/mysql directory.
For context, I am trying to import an sql file and it seems it cannot create the data or directories themselves. Here is the full error:
ERROR 1 (HY000) at line 33: Can't create/write to file '/var/lib/mysql/changelog/changelog.MYI' (Errcode: 2)
In this instance, I'm trying to import a database named changelog
Even after changing the datadir entirely, it still seems to want to write to /var/lib/mysql - Why is that?
You may try to look into section [mysqld] in my.cnf or mysqld.cnf in /etc/mysql/
It could be either due to too many files being open or tmp directory having no permission for your user.
http://alvinalexander.com/mysql/mysql-cant-create-write-file-error-message
I ran into similar error message when trying to create a new database. The final solution is uninstall mysql and reinstall it again. Everything was fine. There are some corruption in the file which caused the errno 2.
I am in a serious problem while installing mysql on ubuntu 12.04 32 bit. when i start mysql with command ''./mysql.server start'' I got this error Manager of pid file quit without updating pid file. I installed ''mysql-5.1.39-linux-i686-glibc23''.
I thoroughly search for the solution to fix this error but cannot resolve it yet. I copied my-medium.cnf file to the /etc directory and rename it by my.cnf also edited this file in the section ''The mysql Server'' and add these lines ''datadir = /exports/disk0/data'' but could fix this problem. Can any one help on this.
The message bout the pid file is kind of a red herring. It just means that the init script /etc/init.d/mysql did not return success. The root cause could be a variety of things, for example file permissions problems in your datadir, or the config file contained an invalid line, or dozens of other possible problems.
When you get the error about the pid file, the first thing you should do is to go read the MySQL error log file. Usually this is in the data directory, and it may be called hostname.err (where "hostname" is the name of the server you installed MySQL).
Search the file for any lines reporting "ERROR" and then use Google to research the error.
I am having some real difficulties finding out exactly what a certain file in the MySQL data directory is used for. (Using Google with its file name is pointless!)
Basically, I need to create some space on the drive that hosts all MySQL data and have noticed a file almost 16GB in size!!
I cant see any reference to a Query file in my config file nor can I match its size up to that of any log files, etc (in case its a log file missing the .log extension). I'm totally stumped!
I would like to know what this file is and how to reduce its size if at all possible?
Thanks in advance for your assistance!
That could be the general query log (I said "could" because the name can be configured by yourself). Look in your my.ini for an entry
log=/path/to/query
Or start the MySQL Administrator, goto "Startup Variables->Log Files" and look for "Query Logfile"
That file is completely unnessasary for your server to run (if you confirmed that the entry log=... exists in your config.
It is just good for debugging.
Try stopping your mysql server, delete it and restart your server again. The file will be recreated.
I also noticed that the slow-query-log ("diamond-slow-log") is large, too.
That file only logs queries that take longer than x seconds (2 by default). That file can be deleted or deactivated, too. But I would keep it since it contains queries that could easily be optimized with an extra index.
Update
there is another way, to confirm that this is the general query log.
Download a windows port of the tail unix command. E.g. this one http://tailforwin32.sourceforge.net/
I often use this on my dev machine to see what is goning on.
Open a shell (cmd.exe) and navigate the folder where that file exists.
Then type
tail -f query
That will print the last few lines of the file and if the file changes every new line.
So if you do a SELECT * FROM table you should see the query in the console output.
I have a large amount of text data I need to import into MySQL. I'm doing this on a MacBook and don't have enough space for it so I want to store it in an external hard drive (I'm not really concerned about speed at this point - this is just for testing).
What's the best way to do it?
Install MySQL on the external hard drive (is this possible on a Mac?)
Install MySQL on the laptop's hard drive and have the tables on the external (how?)
One simple hack is to create an symbolic link replacing your current mysql database file location pointing to the external disk. Google symbolic link.
sample usage would be after you shutdown mysql, change the old mysql db folder name to something else, and create the symbolic link using the ln command like below
ln -s [EXTERNAL DRIVE PATH] [MYSQL DB FOLDER PATH]
Then move all the previous content of the mysql db folder to the new location.
Open /etc/mysql/my.cnf and find the value of the datadir. Alternatively, you can find this out in the mysql monitor with
mysql> select ##datadir;
Stop mysql
sudo systemctl stop mysql
Copy the data from there to your external drive
sudo rsync -av /var/lib/mysql /mnt/myHDD/somedir/mysql
Modify the location of the datadir in my.cnf.
Start mysql again
sudo systemctl start mysql
Verify that everything is still fine and remove the original data dir.
This page contains a more extensive guide but all the additional issues it warns about were not relevant for me on my raspberry PI. I.e. I skipped them and it worked.
For the second option, a tablespace might do the trick:
http://dev.mysql.com/doc/refman/5.1/en/create-tablespace.html
User user658991 answer is halfway there.
After adding the soft link, you will need to add the following line to /etc/apparmor.d/usr.sbin.mysqld beneath the 2 lines to the old mysql folder.
/path/to/mysql/folder/on/the/external/ r
/path/to/mysql/folder/on/the/external/ ** rwk
Without these 2 lines, MySQL fails to start complaining of:
Can't create test file /path/to/mysql/folder/on/the/external/hostname.lower-test
Can't create test file /path/to/mysql/folder/on/the/external/hostname.lower-test
mysqld: Can't change dir to '/path/to/mysql/folder/on/the/external/' (Errcode: 13)
Restart apparmor for the changes to take effect.
sudo invoke-rc.d apparmor restart
With this, MySQL starts normally.