CODEWITHSUNDEEP
mysqllinuxmariadb
Akutasan
Akutasan

Reputation: 159

Could not increase number of max_open_files to more than 4096 (request: 4214)

I have MariaDB + Nginx on Linux Debian 9(stretch). After installing MariaDB it and trying to start it, I got the error saying: [Warning] Could not increase number of max_open_files to more than 4096 (request: 4214). So I googled it and it told me that I should change LimiNOFILE to 10000 in /etc/systemd/system/mysql.service. I did that, did deamon-reload and it did absolutely nothing. I am still getting the same error message. I tried reinstalling MariaDB but that didn't help either. I also added LimitMEMLOCK=10000 at the very end of my file, that didn't change anything.

Full traceback:

Link

Thank you in advance

Upvotes: 7

Views: 36928

Answers (6)

Akutasan
Akutasan

Reputation: 159

This solution will fix your system but will wipe your data (full purge reinstall), so make sure you have backups available.

I solved it by first killing everything that had to do with MariaDB/MySQL via htop and then by reinstalling MariaDB with

$ sudo apt-get purge mariadb-server

And you should check if it's still on the system with:

$ sudo dpkg -l | grep mariadb

And if it is, do:

$ sudo apt-get purge mariadb-common

And then the standard procedure of installing it:

$ sudo apt update

$ sudo apt install mariadb-server

$ sudo mysql_secure_installation

Upvotes: 5

s.abbaasi
s.abbaasi

Reputation: 1114

In my case, I had a syntax error in the MySQL config file: my.cnf

after removing the error line, I started MySQL service successfully.

Upvotes: 0

Alejandro
Alejandro

Reputation: 61

It might be because of the limit set by the SystemD configuration file for the service. If that's the case, you can solve it by editing /usr/lib/systemd/system/mariadb.service and increasing it to the requested value:

LimitNOFILE=4214

... or wathever value you want:

LimitNOFILE=100000

open_files_limit won't have any effect if the operating system or the init system has a lower limit for the user or service.

Upvotes: 6

John Stanfield
John Stanfield

Reputation: 1

Just noting the solution for me was to fix a bad config in the tmpdir variable. It was set to /mysqltmp (probably because /tmp was pretty small). I fixed it with:

mkdir -p /mysqltmp
chown mysql.mysql /mysqltmp

I am guessing setting tmpdir to a dir that doesn't exist or has the wrong permissions triggers this message.

Upvotes: 0

Georg Richter
Georg Richter

Reputation: 7516

Server settings like openfile_files_limits have no effect, if the operating system limits the number of open files, and will always result in an error. Since the server by default is running as user mysql, it can't change the system values (and there is also no code in the server which changes these limits).

Default value of open files on a Linux system is by default 1024, and can be determined by

$> ulimit -n
1024

So in case you have root privileges or you're in the sudo'ers list, just increase this value. man ulimit will give you more information.

Upvotes: 0

nbk
nbk

Reputation: 49393

It is not enough to change it at service level

You must also edit

/etc/mysql/conf.d/limits.cnf

And have these lines in them

[mysqld]
open_files_limit = 10000

Then,

service mysql restart

And you could increase the number to 1000000 in limits.conf and mysql.service

Upvotes: 3

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