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20

So long as the system is doing what you need and is responsive to logins and changes, running 100% CPU is no problem, that's what it's for. Nice only changes the relative priority of processes. In AWS avoid the T series instances if you're using 100% of a CPU, as they give fractional CPU. Over the CPU allocation it's cheaper to get a M (general purpose) / C (...


8

For me, the problem is my /dev/sdb is a GPT partitioned disk. You need to wipe off the GPT records. LVM filters such devices out Run wipefs -a /dev/sdi first to remove any FS/GPT signatures.


8

As a temporary solution you could disable ssl from the command line $ mysql -h <myserver> -u <myuser> -p --ssl-mode=DISABLED password: or by creating a my.cnf file $ cat /etc/my.cnf [client] ssl-mode=DISABLED


7

IPv6 and IPv4 are different protocols. If you only have IPv6 address in Internet space, you cannot connect directly to IPv4 only services. It's really short answer - "no, you can't". TunnelBroker and other free services offers only tunnels in other directions, i.e. from IPv4 to IPv6 and not vice-versa as far as I know. You can set up your own ...


6

Whether you nice or not, running at 100% CPU means you are not processing your jobs as quickly as you could be, if you had more CPU available. The entire system does indeed slow down. The only thing nice does for you is to let you indicate which processes have higher or lower priority and should have more or less of your already limited CPU. If your jobs are ...


5

In systemd, there may be more than one active target at a time. To inspect the list of all currently active targets: systemctl list-units --type target --state active To quickly find out whether a specific target (e.g. user-defined.target) is active or not: systemctl is-active user-defined.target


5

I am pretty sure openssl (you need at least version 1.1.1) is able to do this. openssl s_client -connect www.example.com:443 -tls1_3 See https://raymii.org/s/tutorials/OpenSSL_test_TLSv1.3_connection_with_s_client.html as well.


4

It sounds like your user is missing the skeleton files, the default .bashrc, .bash_profile etc. which are normally copied into a user's home directory from /etc/skel when a user is created. You can copy these files yourself if they are missing or corrupted.


4

Ok, the problem was that systemd support is not compiled by default. You need to compile it explicitelly. I will write a PR to update README.md in sources because this is not explained. This commit is responsible for this behaviour. I found it in this issue: https://github.com/redis/redis/issues/7217 yum install systemd-devel make BUILD_WITH_SYSTEMD=yes ...


4

There is no problem in running a CPU at 100%. Even in the unlikely case that your specific hardware had a cooling problem leading to overheating on , as this is an AWS server, that'd be Amazon's issue, not yours (rest assured, they took that into account in their pricing model) If it didn't do that job, it would be sittling idle, so if you need to have $job ...


3

To get Nano 4 on a CentOS 7 machine it's fairly simple. Head to https://www.nano-editor.org/dist/v4/ and grab the latest .xz (as of February 2020, v4.8 is the latest version). cd to a folder on your machine, e.g. /opt - I do a mkdir -p /opt/apps/nano to store everything. As some people do, you can also download the matching GPG signature and verify it. run ...


3

There are manuals around with bugs, so try this (see comments). If something fails, you need to resolve the issue or it won't work. Some steps are hard to reverse and you may end up with unbootable system so be prepared to rescue/reinstall the system from scratch and have backups. Some commands (distro-sync) takes long time and must not be interrupted so if ...


3

In Nginx configurations, we can specify the maximum number of connections. While please keep in mind that for each new connection, it will be an addition to the extra CPU and memory usage. Active processes: Nginx will use master and child processes to serve the user requests, depending upon the number of connections that we have configured, it will expand ...


3

This should be possible to set in /etc/login.defs with the value LOGIN_TIMEOUT. http://man7.org/linux/man-pages/man5/login.defs.5.html LOGIN_TIMEOUT (number) Max time in seconds for login.


3

Because you selected "rtl8139" (8139cp) as device model to be emulated as network interface card rather "virtio". This still can be changed e.g. using virt-manager or virsh. However it requires a poweroff of the virtual machine, as legacy hardware like RTL8139 can not be hotplugged. See the screenshot at 5.3 Using KVM virtio Drivers for Network Interface ...


3

Backup systems that do not support xfs or ext4, only ext3, should be upgraded or replaced. Modern distros will be using xfs or ext4, which have been stable for a long time and bring features. A safe way to convert file systems is to create new ones and copy files over. If / and /boot are in scope, installing a new host with the desired file system type will ...


3

Hashing the user password is one way operation, you can hash a plain text password and receive a hash. However from a given hash, you cannot restore the original password in plain text. Also if two passwords have the same hash, they are same, but because of salting, different hashes does not guarantee passwords are different. Having that said, to see ...


3

According to yum whatprovides */semodule_package you would need to install policycoreutils-python package.


3

Apologies for leaving what should be a comment as an answer (not enough rep), but: since Ubuntu 20.04, it seems like TLS 1.0 and 1.1 have been disabled system-wide. I don't know how to re-enable it (that's how I stumbled across this question) I have no evidence of this other than openssl s_client -tls1 -connect <some TLSv1-enabled host>:443 doesn't ...


3

I have found a solution assuming your MySQL is using OpenSSL and not yaSSL. Refer to the ssl_cipher configuration variable of MySQL. Configure a list of ciphers that includes the pseudocipher @SECLEVEL=1. For example, ssl_cipher = "DHE-RSA-AES128-GCM-SHA256:AES128-SHA:@SECLEVEL=1" If you need a more permissive but still secure cipherlist, "...


3

For whatever reason, your system has disabled consistent network device naming. This means that instead of using modern device names for interfaces, which remain the same for each NIC, on every boot your NICs may come up with a random eth* identifier that you cannot predict. You should re-enable consistent network device naming, and then reconfigure the NICs ...


3

By default, networking on CentOS 7 and 8 is managed by NetworkManager. It uses a plugin called ifcfg-rh to read the old network service configuration files (used in CentOS 6 and previous versions) such as the one you mentioned and translate them into the appropriate NetworkManager configuration. What has probably happened here is that the interface name has ...


3

The SELinux restricts binaries that can be used in ExecStart to paths that has system_u:object_r:bin_t:s0 attribute set. Typically those are /usr/bin /usr/sbin /usr/libexec /usr/local/bin directories. You need to move the script into one of this directories or change selinux policy to allow systemd to use binaries in the desired location as: chcon -R -t ...


2

solution sudo systemctl unmask --now firewalld sudo systemctl enable firewalld sudo systemctl start firewalld


2

I had the same problem using CentOS 8 and vsftpd. As mentioned in another post you have to load the kernel module "nf_conntrack_ftp" (which was already the case in CentOS 8) and enable "nf_conntrack_helper" in kernel settings: echo 1 > /proc/sys/net/netfilter/nf_conntrack_helper Add this line to /etc/sysctl.conf (or /etc/sysctl.d/10-nf_conntrack_helper....


2

Just to add to the accepted answer, I recently updated redis and encountered the same problem. The configuration file /etc/redis.conf already had the line daemonize no and I still had that problem. I fixed it by telling redis to interact with the supervisor systemd: # /etc/redis.conf supervised auto # or systemd For reference, the system I was using was ...


2

If you downladed the GenericCloud image from cloud.centos.org, it does not have any users created. You can change the root password using virt-customize from libguestfs-tools package: # virt-customize -a image_name.qcow2 --root-password password:your.great.password Just keep in mid that this is not secure. After you login as root, you should create a sudo ...


2

With RPM Package Manager you can simply provide foo 4 bar. This is a stupid dummy spec example, purists will remove the rpmlint ;-) warnings: $ cat ~/rpmbuild/SPECS/provides-httpd.spec Summary: Dummy package to provide with httpd for httpd24 Name: provides-httpd Version: 0.1 Release: 1%{?dist} License: GPLv2 Requires: httpd24-httpd Provides: ...


2

Sometime because of unsupported SFP interface won't come up so solution is to create following file to allow unsupported SFP. create file /etc/modprobe.d/ixgbe.conf alias ens2f0 ixgbe alias ens2f1 ixgbe options ixgbe allow_unsupported_sfp=1 Do rmmod ixgbe; modprobe ixgbe add in /etc/default/grub file to fix the issue permanently ixgbe.allow_unsupported_sfp=...


2

GRUB_TERMINAL_OUTPUT="serial console" Change this to: GRUB_TERMINAL="serial console" (also you have a duplicate GRUB_TERMINAL_OUTPUT; remove it)


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