How to solve the problem of character set when logging in to Linux

Character set error always exists

locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory

background

The company has a Jenkins server. Due to historical reasons, it has been using CentOS 6.5. Suddenly, when logging in, it prompted that there was a problem with the character set. I have actually been using CentOS 7 for a long time and have never encountered such a problem. I was also confused during the troubleshooting process.

There were various character set errors and invalid settings. After n days of continuous investigation, I found that it was caused by glibc. During the process of shooting the error, I also found that version 2.15 could not be used. Damn it, I quickly made a note of it.

Troubleshooting process

1. The direct response was the character set. I checked multiple documents on Baidu, various configurations, and various update plug-ins, but they didn't work. In addition, I had other work at hand, which delayed it for several days.

I thought about it carefully today. Since no character set is effective, it should not be a character set problem. There must be a problem in the loading process. However, the server has not done any work in the past few days. I was bored and browsed Baidu. Suddenly I saw a post related to glibc. Then I continued to search Baidu. There are really other guys who have encountered similar problems. They said that make localedata/install-locales should be added during compilation. After understanding the solution, I tried it immediately.

2. The system default is 2.12. I upgraded to 2.14 because of some plug-in requirements. I originally wanted to downgrade to 2.12, but then I thought, why not download 2.15 and recompile, theoretically all the problems should be solved.

3. Find glibc-2.15 resources online, download, compile, and install. After routine operations, point the /lib64/libc.so.6 soft link to glibc-2.15. Then the error Illegal instruction (core dumped) is reported again, and the system cannot log in. Quickly repair LD_PRELOAD=/lib64/libc-2.12.so ln -sf /lib64/libc-2.12.so /lib64/libc.so.6 and downgrade to 2.12 first. At least the character set problem is solved, but this doesn’t work. After many attempts to upgrade to 2.15, it finally failed, and no relevant solution was found on the Internet.

4. I had no choice but to think it might be a system compatibility issue. I didn’t give up and tried to upgrade to 2.17 again. I still operated normally and this time it finally worked. . .

Specific process

1. Check the system glibc version library

strings /lib64/libc.so.6 |grep GLIBC_

I found that the highest is 2.12, and I am going to upgrade to 2.17. Don't install 2.15. I don't know if it's my fault, but I can't install it anyway.

2. Download and install

Enter the download directory/data/install and execute the command. I won’t explain the details. You will understand.

wget https://ftp.gnu.org/gnu/glibc/glibc-2.17.tar.gz

tar xvf glibc-2.17.tar.gz

mkdir glibc-build-2.17

cd glibc-build-2.17/

../glibc-2.17/configure --prefix=/usr --disable-profile --enable-add-ons --with-headers=/usr/include --with-binutils=/usr/bin

make -j8 && make install && make localedata/install-locales

3. Verification

strings /lib64/libc.so.6 | grep GLIBC

There is no need to replace the /lib64/libc.so.6 file, and the file soft link already points to glibc-2.17, and you are done.

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