1. Problem environment
virtual machine: VMware 16
Windows system: Windows 10
linux system: CentOS 7.6
interactive software: SecureCRT 8.7
2. Prompt
3. Solution
click “options”, select “session options”, as shown in the figure below, click “SSH2”, then modify “username”, and click “OK”
4. reconnect
connect successfully
Tag Archives: cents
[Solved] Zabix web Access Error: Database error No route to host
Generally, the problem is that the database address of ZABBIX has changed, so we need to update the configuration file of ZABBIX
1. Change zabbix_server.conf file
vim /etc/zabbix/zabbix_server.conf
2. Modify zabbix.conf.php file
3. Restart ZABBIX service
systemctl restart zabbix-server.service
[Solved] Module yaml error: Unexpected key in data: static_context
Problem description
An error occurs when executing the linux
command on centos8
[[email protected] ~]# dnf update epel-release
Repository epel is listed more than once in the configuration
Last metadata expiration check: 2:24:16 ago on Mon 25 Apr 2022 07:27:51 AM CST.
Module yaml error: Unexpected key in data: static_context [line 9 col 3]
Module yaml error: Unexpected key in data: static_context [line 9 col 3]
Dependencies resolved.
Nothing to do.
Complete!
Solution:
It can be solved by upgrading libmodulemd
(DNF upgrade libmodulemd
). The problem can be fixed in libmodulemd-2.13.0-1.fc33
.
[Solved] Centos error: collect2: fatal error: cannot find ‘ld‘
When executing a compiled file in Linux (. /configure) with collect2: fatal error: cannot find ‘ld’, which is also preceded by gcc: error: unrecognized command line option -V and configure: error: C compiler cannot create executables. When you find that your gcc and the corresponding dependency packages are installed, you still get the error. At this point you look under /usr/bin/ to see if there is an ld. which ld is not found, but you find a file called ld.gold under /usr/bin by running ls -l |grep ld.
Solution:
Copy ld.gold under /usr/bin/ (do not delete the original file) and rename it to ld. You can also create a soft connection.
Re-execute the compilation
Problem found solved!
Brief description.
gcc compiles the source code to .o, then linker links the .o to .so or executable, linker can use ld.bfd, ld.gold or lld.
[Solved] Nacos Cluster startup error: error=‘Cannot allocate memory‘ (errno=12)
Problem discovery
1. Start one of the Nacos clusters
2. Query the number of starts through the number of starts in the cluster command
ps -ef|grep nacos|grep -v grep|wc -l
This is the second startup. One has been started before, so the problem comes. Why is it still one after the second startup
3. Use the tail-f command to read the contents of the file loop, monitor the growth of the file and find out the reason
tail -f 文件路径 #The file path is given after the start command
Normal start
Second startup error
From the Nacos startup log information, we can see that the memory is insufficient
4. Check the memory usage through the free -h command
There is only 70m of available memory left
5. By viewing startup.sh file to view the JVM startup command
– xms2g represents 2G of initially allocated memory
– xmx2g represents the maximum value of JVM memory
– xmn1g represents 1g of Cenozoic memory;
Solution:
1. Increase system memory
2. Modify the startup parameters of the JVM in the startup script and reduce the memory allocated to the JVM
Allocate according to your current usage mode and the memory of your virtual machine
After modification, it is started successfully
yum: Error: Failed to download metadata for repo ‘aliyun-AppStream‘: Cannot download repomd.xml
preface
centos8 stopped the service of source on December 31, 2021
The current system is CentOS
[[email protected] ~]# cat /etc/centos-release
CentOS Linux release 8.5.2111
[[email protected] ~]#
Yum error message
[[email protected] ~]# yum install ipmitool
CentOS-8 - AppStream 439 B/s | 2.3 kB 00:05
Errors during downloading metadata for repository 'aliyun-AppStream':
- Status code: 404 for https://mirrors.aliyun.com/centos-Vault/8.5.2111/BaseOS/x86_64/os/repodata/repomd.xml (IP: 182.105.147.113)
Error: Failed to download metadata for repo 'aliyun-AppStream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
[[email protected] ~]#
Solution
1. Execute the following commands
[[email protected] ~]#cd /etc/yum.repos.d/
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# ls -lh
total 24K
-rwxr-xr-x. 1 root root 288 Mar 22 20:07 CentOS-AppStream.repo
-rwxr-xr-x. 1 root root 276 Mar 22 20:07 CentOS-BaseOS.repo
-rwxr-xr-x. 1 root root 3.0K Mar 22 20:07 CentOS-Base.repo
-rwxr-xr-x. 1 root root 279 Mar 22 20:07 CentOS-Extras.repo
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
[[email protected] yum.repos.d]# sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# yum update -y
Repository base is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Repository PowerTools is listed more than once in the configuration
Repository AppStream is listed more than once in the configuration
CentOS-8 - AppStream 437 B/s | 2.3 kB 00:05
Errors during downloading metadata for repository 'aliyun-AppStream':
- Status code: 404 for https://mirrors.aliyun.com/centos-Vault/8.5.2111/BaseOS/x86_64/os/repodata/repomd.xml (IP: 124.225.134.244)
Error: Failed to download metadata for repo 'aliyun-AppStream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
2. If the problem is not solved, do the following:
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
--2022-03-22 20:08:42-- https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
Resolving mirrors.aliyun.com (mirrors.aliyun.com)... 124.225.134.241, 124.225.134.239, 124.225.134.243, ...
Connecting to mirrors.aliyun.com (mirrors.aliyun.com)|124.225.134.241|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2495 (2.4K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS-Base.repo’
/etc/yum.repos.d/CentOS-Base.repo 100%[===================================================================================================================>] 2.44K --.-KB/s in 0s
2022-03-22 20:08:47 (49.0 MB/s) - ‘/etc/yum.repos.d/CentOS-Base.repo’ saved [2495/2495]
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# yum clean all
Repository base is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Repository PowerTools is listed more than once in the configuration
Repository AppStream is listed more than once in the configuration
18 files removed
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# yum makecache
Repository base is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Repository PowerTools is listed more than once in the configuration
Repository AppStream is listed more than once in the configuration
CentOS-8 - AppStream 428 B/s | 2.3 kB 00:05
Errors during downloading metadata for repository 'aliyun-AppStream':
- Status code: 404 for https://mirrors.aliyun.com/centos-Vault/8.5.2111/BaseOS/x86_64/os/repodata/repomd.xml (IP: 119.41.210.242)
Error: Failed to download metadata for repo 'aliyun-AppStream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
[[email protected] yum.repos.d]#
3. Then perform the following operations
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# ls -lh
total 24K
-rwxr-xr-x. 1 root root 288 Mar 22 20:07 CentOS-AppStream.repo
-rwxr-xr-x. 1 root root 276 Mar 22 20:07 CentOS-BaseOS.repo
-rwxr-xr-x. 1 root root 3.0K Mar 22 20:07 CentOS-Base.repo
-rwxr-xr-x. 1 root root 279 Mar 22 20:07 CentOS-Extras.repo
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# mkdir bak
[[email protected] yum.repos.d]# mv *.repo bak
[[email protected] yum.repos.d]# ls
bak
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
--2022-03-22 20:10:10-- https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
Resolving mirrors.aliyun.com (mirrors.aliyun.com)... 124.225.134.239, 124.225.134.241, 124.225.134.243, ...
Connecting to mirrors.aliyun.com (mirrors.aliyun.com)|124.225.134.239|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2495 (2.4K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/CentOS-Base.repo’
/etc/yum.repos.d/CentOS-Base.repo 100%[==================================================================>] 2.44K --.-KB/s in 0s
2022-03-22 20:10:15 (98.3 MB/s) - ‘/etc/yum.repos.d/CentOS-Base.repo’ saved [2495/2495]
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# yum clean all
0 files removed
[[email protected] yum.repos.d]# yum makecache
CentOS-8.5.2111 - Base - mirrors.aliyun.com 454 kB/s | 4.6 MB 00:10
CentOS-8.5.2111 - Extras - mirrors.aliyun.com 1.0 kB/s | 10 kB 00:10
CentOS-8.5.2111 - AppStream - mirrors.aliyun.com 571 kB/s | 8.4 MB 00:15
Metadata cache created.
[[email protected] yum.repos.d]# ls
bak CentOS-Base.repo
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]#
[[email protected] yum.repos.d]# yum install ipmitool
Last metadata expiration check: 0:00:27 ago on Tue 22 Mar 2022 08:10:54 PM CST.
Dependencies resolved.
=================================================================================================================================================================================================================
Package Architecture Version Repository Size
=================================================================================================================================================================================================================
Installing:
ipmitool x86_64 1.8.18-18.el8 AppStream 395 k
Transaction Summary
=================================================================================================================================================================================================================
Install 1 Package
Total download size: 395 k
Installed size: 1.1 M
Is this ok [y/N]: y
Downloading Packages:
ipmitool-1.8.18-18.el8.x86_64.rpm 71 kB/s | 395 kB 00:05
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 71 kB/s | 395 kB 00:05
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : ipmitool-1.8.18-18.el8.x86_64 1/1
Running scriptlet: ipmitool-1.8.18-18.el8.x86_64 1/1
Verifying : ipmitool-1.8.18-18.el8.x86_64 1/1
Installed:
ipmitool-1.8.18-18.el8.x86_64
Complete!
[[email protected] yum.repos.d]#
At this point, you can use the yum install command.
CentOS7 Failed to start LSB: Bring up/down networking [How to Solve]
Solution:
Disable NetworkManager:
1. systemctl stop NetworkManager
2. systemctl disable NetworkManager
Restart network:
- service network restart
[Solved] Error: Failed to download metadata for repo ‘appstream‘
Solution:
1. Back up CentOS Linux baseos Repo file
mv CentOS-Linux-BaseOS.repo CentOS-Linux-BaseOS.repo.backup
2. Update baseos Repo file
curl -o /etc/yum.repos.d/CentOS-Base.repo
3. Generate new Yum cache
yum makecache
[Solved] Yum Install Software Error: Invalid configuration value: failovermethod=priority…
Error 1:
Invalid configuration value: failovermethod=priority in /etc/yum.repos.d/CentOS-Linux-BaseOS.repo; Configuration: OptionBinding with id "failovermethod" does not exist
CentOS Linux 8 - AppStream 6.3 kB/s | 2.3 kB 00:00
Errors during downloading metadata for repository 'appstream':
- Status code: 404 for http://mirrors.cloud.aliyuncs.com/centos/8/AppStream/x86_64/os/repodata/repomd.xml (IP: 100.100.2.148)
Error: Failed to download metadata for repo 'appstream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
The current environment is:
[[email protected] yum.repos.d]# uname -srm
Linux 4.18.0-348.2.1.el8_5.x86_64 x86_64
CentOS version:
[[email protected] yum.repos.d]# cat /etc/redhat-release
CentOS Linux release 8.5.2111
Solution:
1. Find CentOS related directory, backup CentOS-AppStream, CentOS-Base files, generally CentOS directory is under /etc/yum.repos.d folder, as follows:
Backup:
cp CentOS-Linux-AppStream.repo CentOS-Linux-AppStream.repo1
cp CentOS-Linux-BaseOS.repo CentOS-Linux-BaseOS.repo1
2. Edit the files CentOS-Linux-AppStream.repo,CentOS-Linux-BaseOS.repo for string replacement:
vi CentOS-Linux-BaseOS.repo
# esc 键盘 : 命令模式下执行:
%s/mirrors.cloud.aliyuncs.com/mirrors.aliyun.com/g
# 继续执行:
%s/$releasever/$releasever-stream/g
vi CentOS-Linux-AppStream.repo
# esc 键盘 : 命令模式下执行:
%s/mirrors.cloud.aliyuncs.com/mirrors.aliyun.com/g
# 继续执行:
%s/$releasever/$releasever-stream/g
3. Execute the order:
yum makecache
yum update
Command execution effect:
[[email protected]k901ftf2vfscwc1Z yum.repos.d]# yum update
Invalid configuration value: failovermethod=priority in /etc/yum.repos.d/CentOS-Linux-epel.repo; Configuration: OptionBinding with id "failovermethod" does not exist
Last metadata expiration check: 0:01:22 ago on Wed 09 Mar 2022 10:20:01 AM CST.
Error:
Problem: package centos-stream-release-8.6-1.el8.noarch requires centos-stream-repos, but none of the providers can be installed
- package centos-linux-repos-8-3.el8.noarch conflicts with centos-repos(8) provided by centos-stream-repos-8-2.el8.noarch
- package centos-stream-repos-8-2.el8.noarch conflicts with centos-repos(8) provided by centos-linux-repos-8-3.el8.noarch
- package centos-linux-repos-8-3.el8.noarch conflicts with centos-repos(8) provided by centos-stream-repos-8-3.el8.noarch
- package centos-stream-repos-8-3.el8.noarch conflicts with centos-repos(8) provided by centos-linux-repos-8-3.el8.noarch
- package centos-linux-repos-8-3.el8.noarch conflicts with centos-repos(8) provided by centos-stream-repos-8-4.el8.noarch
- package centos-stream-repos-8-4.el8.noarch conflicts with centos-repos(8) provided by centos-linux-repos-8-3.el8.noarch
- cannot install the best update candidate for package centos-linux-release-8.5-1.2111.el8.noarch
- problem with installed package centos-linux-repos-8-3.el8.noarch
(try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)
Execute the command Yum install * expect * again, and the results are as follows:
[[email protected] yum.repos.d]# yum install *expect*
Invalid configuration value: failovermethod=priority in /etc/yum.repos.d/CentOS-Linux-epel.repo; Configuration: OptionBinding with id "failovermethod" does not exist
Last metadata expiration check: 0:07:00 ago on Wed 09 Mar 2022 10:20:01 AM CST.
Package python3-pexpect-4.3.1-3.el8.noarch is already installed.
Dependencies resolved.
===========================================================================================================
Package Architecture Version Repository Size
===========================================================================================================
Installing:
expect x86_64 5.45.4-5.el8 baseos 267 k
python3-aexpect noarch 1.6.2-1.el8 epel 93 k
Installing dependencies:
tcl x86_64 1:8.6.8-2.el8 baseos 1.1 M
Transaction Summary
===========================================================================================================
Install 3 Packages
Total download size: 1.5 M
Installed size: 5.2 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): python3-aexpect-1.6.2-1.el8.noarch.rpm 467 kB/s | 93 kB 00:00
(2/3): expect-5.45.4-5.el8.x86_64.rpm 282 kB/s | 267 kB 00:00
(3/3): tcl-8.6.8-2.el8.x86_64.rpm 351 kB/s | 1.1 MB 00:03
-----------------------------------------------------------------------------------------------------------
Total 461 kB/s | 1.5 MB 00:03
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : tcl-1:8.6.8-2.el8.x86_64 1/3
Running scriptlet: tcl-1:8.6.8-2.el8.x86_64 1/3
Installing : expect-5.45.4-5.el8.x86_64 2/3
Installing : python3-aexpect-1.6.2-1.el8.noarch 3/3
Running scriptlet: python3-aexpect-1.6.2-1.el8.noarch 3/3
Verifying : expect-5.45.4-5.el8.x86_64 1/3
Verifying : tcl-1:8.6.8-2.el8.x86_64 2/3
Verifying : python3-aexpect-1.6.2-1.el8.noarch 3/3
Installed:
expect-5.45.4-5.el8.x86_64 python3-aexpect-1.6.2-1.el8.noarch tcl-1:8.6.8-2.el8.x86_64
Complete!
OK, you can install yum
Note: in actual use, if there is no CentOS-AppStream.repo related files, do not operate on them
Eg: install git:
[[email protected] yum.repos.d]# yum -y install git
Invalid configuration value: failovermethod=priority in /etc/yum.repos.d/CentOS-Linux-epel.repo; Configuration: OptionBinding with id "failovermethod" does not exist
Last metadata expiration check: 0:07:51 ago on Wed 09 Mar 2022 10:20:01 AM CST.
Dependencies resolved.
===========================================================================================================
Package Architecture Version Repository Size
===========================================================================================================
Installing:
git x86_64 2.31.1-2.el8 appstream 161 k
Installing dependencies:
git-core x86_64 2.31.1-2.el8 appstream 4.7 M
git-core-doc noarch 2.31.1-2.el8 appstream 2.6 M
perl-Error noarch 1:0.17025-2.el8 appstream 46 k
perl-Git noarch 2.31.1-2.el8 appstream 78 k
perl-TermReadKey x86_64 2.37-7.el8 appstream 40 k
Transaction Summary
===========================================================================================================
Install 6 Packages
Total download size: 7.7 M
Installed size: 38 M
Downloading Packages:
(1/6): git-2.31.1-2.el8.x86_64.rpm 299 kB/s | 161 kB 00:00
(2/6): perl-Error-0.17025-2.el8.noarch.rpm 185 kB/s | 46 kB 00:00
(3/6): perl-Git-2.31.1-2.el8.noarch.rpm 290 kB/s | 78 kB 00:00
(4/6): perl-TermReadKey-2.37-7.el8.x86_64.rpm 148 kB/s | 40 kB 00:00
(5/6): git-core-doc-2.31.1-2.el8.noarch.rpm 385 kB/s | 2.6 MB 00:07
(6/6): git-core-2.31.1-2.el8.x86_64.rpm 394 kB/s | 4.7 MB 00:12
-----------------------------------------------------------------------------------------------------------
Total 640 kB/s | 7.7 MB 00:12
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : git-core-2.31.1-2.el8.x86_64 1/6
Installing : git-core-doc-2.31.1-2.el8.noarch 2/6
Installing : perl-TermReadKey-2.37-7.el8.x86_64 3/6
Installing : perl-Error-1:0.17025-2.el8.noarch 4/6
Installing : perl-Git-2.31.1-2.el8.noarch 5/6
Installing : git-2.31.1-2.el8.x86_64 6/6
Running scriptlet: git-2.31.1-2.el8.x86_64 6/6
Verifying : git-2.31.1-2.el8.x86_64 1/6
Verifying : git-core-2.31.1-2.el8.x86_64 2/6
Verifying : git-core-doc-2.31.1-2.el8.noarch 3/6
Verifying : perl-Error-1:0.17025-2.el8.noarch 4/6
Verifying : perl-Git-2.31.1-2.el8.noarch 5/6
Verifying : perl-TermReadKey-2.37-7.el8.x86_64 6/6
Installed:
git-2.31.1-2.el8.x86_64 git-core-2.31.1-2.el8.x86_64 git-core-doc-2.31.1-2.el8.noarch
perl-Error-1:0.17025-2.el8.noarch perl-Git-2.31.1-2.el8.noarch perl-TermReadKey-2.37-7.el8.x86_64
Complete!
[[email protected] yum.repos.d]# git --version
git version 2.31.1
Error 2:
Invalid configuration value: failovermethod=priority in /etc/yum.repos.d/CentOS-Linux-epel.repo; Configuration: OptionBinding with id "failovermethod" does not exist
Repository extras is listed more than once in the configuration
CentOS Linux 8 - AppStream 6.7 kB/s | 2.3 kB 00:00
Errors during downloading metadata for repository 'appstream':
- Status code: 404 for http://mirrors.cloud.aliyuncs.com/centos/8/AppStream/x86_64/os/repodata/repomd.xml (IP: xxx.xxx.xxx.xxx)
Error: Failed to download metadata for repo 'appstream': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
Solution
Enter the file /etc/yum.repos.d/CentOS-Epel.repo
, and comment out failovermethod=priority
:
OK, you can also install yum
How to Solve Yum Error: db5 error(30973)
Problem error: failed to open rpmdb. db5 error(30973)
error: rpmdb: BDB0113 Thread/process 8442/140713489532992 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 - (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.main:
Error: rpmdb open failed
[[email protected] ~]# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
error: rpmdb: BDB0113 Thread/process 8442/140713489532992 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 - (-30973)
error: cannot open Packages database in /var/lib/rpm
CRITICAL:yum.cli:Yum Error: Error: rpmdb open failed
The reason why rpm is damaged: the database needs to be rebuilt.
Solution: clear the original link through the command and re-establish it.
[[email protected] ~]# rm -rf /var/lib/rpm/_db* #Delete the original
[[email protected] ~]# rpm --rebuilddb # New
[[email protected] ~]# yum clean all # Clear all yum caches
It can be used normally at present
[Solved] Sshd startup error: Failed at step CGROUP spawning /usr/sbin/sshd: No space left on device
sshd restart error:
systemctl restart sshd.service
The screenshot is as following:
Error Messages:
Failed at step CGROUP spawning /usr/sbin/sshd: No space left on device Failed to create cgroup /system.slice/sshd.service: No such file or directory
The reason for this is that the cgroup is not mounted.
Solution:
Mount the cgroup directory
mount -t tmpfs cgroup_root /sys/fs/cgroup
umount -t tmpfs cgroup_root /sys/fs/cgroup
umount /sys/fs/cgroup
then restart to connect normally
systemctl start sshd.service
Firewall Status View Error: service iptables status [How to Solve]
View firewall status service iptables status
iptables.service cannot be found, use the following command to install: yum install iptables-services
Check the firewall status again