Newest 'centos7' Questions

Q&A for system and network administrators

+50

Intermittent issues uploading via FTP (fatal: protocol version) - Connections not being removed?

Client is experiencing intermittent problems uploading files to the FTP server. Sometimes it works and sometimes it doesn't. It seems they can login ok (the vsftpd logs show successful logins), but ...

CentOS7 Targetcli Configuration lost after server reboot

Targetcli configuration got lost after server was rebooted, i tried to restore configuration from backup files with targetcli restoreconfig <backupFile> configuration is not restored output ...

sending and receiving mails between public and private domain [closed]

I want to send and receive mails from gmail server (public domain) to and from zimbra server which is on a private domain. can anyone send me complete configuration both on zimbra mail server and ...

Centos7 disable IP Redirect sending on IPSec VPN Server

When using StrongSwan as an IPSEC S2S VPN Gateway, ICMP redirects are being sent to machines behind the right side. I have added the following lines to /etc/sysctl.conf: net.ipv4.conf.all....

I can’t connect to my Azure VM

After I used this command: ifdown eth0 can't connect to my VM (centos 6 ) with ssh on cloud microsft azure. How can I fix it?

centos 7 not allowing inbound tcp connection on port 80 when connected to two network interfaces

I connected two network interfaces to a server running centOS 7 and I configured the public zone to allow inbound tcp connections on port 80 & 443, I then set one of the network interfaces to the ...

Very Slow VPS server [closed]

I am junior in server management and I am searching to find out why my server is too slow. First of all, I have to mention its characteristics: 3 vCores 1024MB Ram 80 GB Sata 7,2K HDD I have also ...

rsync one way incremental backup jobs from Windows to CentOS

I have an rsync job that incrementally copies files from a Windows server that I have in the field to another Windows Server that I have here in my data center. The incremental jobs run perfectly and ...

CentOS 7 - SMTPS on Postfix is not working right

First, I am a CentOS 7 newbie. I am running an email server on CentOS 7, I am currently having issue with setting SMTPS up on postfix. BTW, imap over SSL on port 993 is working fine. Port 465 and ...

Centos 7 Failed to start LSB: VirtualBox Linux Additions kernel modules [migrated]

Recently ran updates on one of my Centos 7 Development Environments (server) which is running though Parallels on Mac OSX, when I went to start the VM recently I received this output: [FAILED] Failed ...

Unable to open ftp port 21 on centos using firewalld

I am trying to install vsftpd on Centos 7. I can connect to the server from localhost, but not connect to it from remote machines. I am somewhat new to the topic of system and network administration....

Where can I find my own server's DNS records? Need to update it for a third party mail delivery system - SparkPost?

I have a forum running which occasionally sends out emails to registered users. We are switching our forum engine from vBulletin to Discourse. While configuring Discourse, I need to provide the ...

Is there a way (non network-based) to share host (ubuntu) file system with guest (centos 7) using libvirt?

I am trying to use virsh and domain xml to launch a Centos 7 guest from ubuntu 16.04 LTS host. The "filesystem" node that i am using in domain xml is as below: <filesystem type='mount' accessmode='...

ERR_TOO_MANY_REDIRECTS using Virtual Hosts

I'm getting an ERR_TOO_MANY_REDIRECTS when entering my website, using Google Chrome. I'm not using any rewrite module. This is my website configuration: (Literally a Virtual Host) <VirtualHost *:...

Centos 7 not booting from Dell Perc 6i raid 0

I recently obtained a poweredge 2900 (unknown generation) tower with a perc 6i controller and built and initalize a raid 0 array from 2 146gb sas drives. During the centos installation it does see and ...

How to make logger log PID on CentOS7

i found documentation for logger stating one can use --id=$$ to log the pid of the calling script. unfortunatly this is not working with logger in centos7. what is the proper way of logging pid to ...

SMTP Error (450): Failed to add recipient “example@gmail.com” [on hold]

Full error: SMTP Error (450): Failed to add recipient "example@gmail.com" (4.1.1 <example@gmail.com>: Recipient address rejected: User unknown in virtual mailbox table). Alright so this is ...

Sendmail only sending locally

I wrote a script to send me an email if an existing process is not available, so I installed sendmail as suggested elsewhere. I know why I'm having the issue I'm having, but either I do not know how ...

VMWare vSphere, CentOS7 and customizations

I'm running the latest version of esxi (6.5) and vCenter. I created a VM template based on CentOS7, and used a LVM-based disk layout. However, now vSphere customizations don't work, and I'm getting ...

Name resolution and DNS registration for a CentOS 7 Azure VM

I have a Linux VM (CentOS 7.2) running on Azure, which is configured as a DHCP client because this is required by the Azure platform; Azure DHCP correctly supplies a network configuration to the VM, ...

Permission difficulties with NFS-mounted /var/spool/mail for dovecot and procmail

My mail server setup worked for years. Recently I've started experiencing the following problem: Mail setup: sendmail+dovecot+procmail Host file server: CentOS 6.8, NFS exports mail directories to......

“Connection refused” by CentOS7 when trying to connect remotely with SSH

I installed the latest CentOS 7 version 1611 on a Hyper-V VM with static IP. Network and firewall seem to be set up correctly. Now I am trying to simply log into it remotely from Putty. I get "...

Issue With Linux Process [closed]

I'm running Centos 7 On my server. and am having script which is using curl. my issue that while I'm checking the process of my server after running the script it's keep giving me an little number ...

Which IP is sending most traffic to server

I have a centos 7 server which started to get twice the amount of traffic two hours ago. how can I see which IP addresses generate the most traffic to my server? The server is used to host influxDB ...

Downgrade Centos 7.2 to 7.1 [duplicate]

First of all, i understand that this is not a recommended approach to downgrade centos 7.2 to 7.1, the best course of action is to reload the system. However, due to some reasons, i cann't reload ...

TCP window scale mismatch between CentOS 7 and Windows 2012 R2

Having TCP client on CentOS 7 and TCP listener on Windows 2012 R2, I observed through wireshark, sysinternals procmon and ss -bitmonz command, that the tcp client wscale is 7 (scale factor 128) while ...

blockdev --getbsz reports different blocksize when partition is mounted

I have a centos 7 machine and am trying to mount an xfs parition with a 4096 kb block size. when the xfs patition is unmounted: blockdev --getbsz /dev/xvdc 4096 when mounting using mount -t xfs ...

Create zfs pool that allows replacing one of the disks with a slightly smaller disk

This is a quation regarding zfs on Linux (CentOS 7). I have a very simple setup with two 8 TB disks, one disk mirroring the other. zpool create -f -o ashift=12 $zpoolName mirror $disksById In case ...

Apache serve files with different URL encode

I got an error when i try to load a file image on my staging server, it seems is about encoding. When i access to the following URL: http://example.com/sites/default/files/2016-12/Articulaci%C3%B3n....

Nginx installation with temporary url on centos 7

Greeting, I have a new dedicated server with centos 7. For the testing purpose i need to use nginx on a temporary url like "127.0.0.1/~linux" but the issue remains how should i post the nginx to this ...

FirewallD - Trusted Zones / Drop Zone and Tracerouting

Im using CentOS 7 and I have an issue where I am trying to lock down a server to only accept SSH from any private IP ranges of 10.0.0.0/8 which is in the work zone, and 10.0.20.0/24 for any connection ...

sshd: MaxAuthTries is ignored if it is greated than 3

I am using CentOS v7, and I tried to set MaxAuthTries 6 though this doesn't seem to work. I am using PAM so the property UsePAM yes is set. I am not sure if it is a bug or something else blocking the ...

Static IP after reboot conflict with repository : [Errno 256] No more mirrors to try

I install CentOS-7-x86_64-Minimal-1611 on vmware. In the first part, after enabled dhclient I can install and download using commands but I set static IP to avoid to use dhclient command every after ...

Linux Load Average in Billions with Thread Count Only in Thousands?

One of our servers is currently sitting with its load averages in the billions (with a b), while reporting that it only has 1,031 resident threads: top - 12:04:26 up 2 days, 19:03, 68 users, load ...

additional rpms to offline centos iso

I try to create custom iso of CentOS Linux release 7.3.1611 (Core) with additional rpms installation. I downloaded all rpms, put them in Packages directory, recreate repodata with following command: ...

CentOS 7 PV images?

I'm trying to install CentOS 7 under Xen as a PV DomU, but I can't find the needed initrd.img and vmlinuz images. Is there anywhere that I can download them, or if I need to, how can I generate them? ...

Cron Error getpwnam() failed for DB back up

Trying to learn how to implement a cron job using php. cron is formatted like so /etc/crontab * 13 * * * /usr/bin/php /var/www/path/to/file/database-bkup-test.php &>/tmp/mycroncommand.log ...

PPTP Passthrough Centos 7/Firewalld router to Windows Server

I have a Centos 7 server running firewalld to allow public services to access internal services on a separate VLAN (dual NICs). I imported a Windows VM but I do not know what rules I need to put in ...

Configure multiple ip on same vlan on centos 7 machine

My existing network file looks like below # cat ifcfg-ens1.200 DEVICE=ens1.200 BOOTPROTO=static ONBOOT=yes IPADDR=172.16.2.10 NETMASK=255.255.255.0 USERCTL=no NETWORK=172.16.2.0 VLAN=yes How to ...

Centos7 - link up, but no DCHP, unable to bring up next working interface

I have following configuration: server has two network interfaces, both are attached to switch (and will become LOWER_UP after been made up). One of those interfaces will have DHCP server with a lease....

VMware customization specification for Linux CentOS server not prompting for gateway

So I created a customization specification in VMware 6.0.0 and configured it so that it prompts the user whan a vm is deployed from my CentOS 7 template. The ip address, subnet mask and hostname are ...

Cloud-init is failing to execute awscli command in User Data

Need help to fix the error and enable the instance to run issue free User Data script. Issue: cloud-init is unable to execute awscli command. I have mentioned a custom script (which will be present ...

nmcli is not working in Kickstart script

I have the following commands in a Kickstart post-install script: firewall-offline-cmd --new-zone=management firewall-offline-cmd --zone=management --add-service=ssh --add-service=snmp firewall-...

CentOS 7 MariaDB Error “Failed to start mariadb.service: Unit not found.” [closed]

I am somewhat new to Linux, testing various LAMP setups in Virtualbox on Windows. Currently I have a Centos 7 VM that I am trying to install MariaDB on. I am following instructions here: http://www....

Expand NTFS formatted disk image

I have a CentOS 7 server that I installed targetcli on and am using several fileio based backstores as LUNs on a Windows server. The .img files are created directly from within the targetcli shell. ...

Firewalld CentOS 7 Routing IPv6

I try to set up a Centos 7 VM to route IPv6 traffic to another, interal Centos 7 VM. If i disable firewalld, all works, but that should not be the solution.. I've two interfaces: ens32 external (...

failed to read BIOS file: No such file or directory

I'm trying to install CentOS 7 in a VM from an ISO, but I keep getting an the error libxl_dom.c:892:libxl__load_hvm_firmware_module: failed to read BIOS file: No such file or directory. Here is my ...

Authentication is required to manage system services or units.

I have a strange issue whenever trying to stop/start a daemon as a regular user, it asks to authenticate with the credentials of another regular user - for example: [bob@server ~]$ systemctl stop ...

Unable to access CentOS 7 Postgresql Server from another CentOS7 using PHP and PDO

The Beginning Server 1 is my CentOS 7 production server. It contains Apache, ssh and a Postgresql database. Server 2 is my CentOS 7 test server. It contains Apache, ssh and a test database. Both ...

sshd is already running though keeps trying to start

I have a Centos 7 server and sshd is running and accepting connections just fine. The problem is, that messages log keeps reporting failed sshd startup attempts and secure log keeps reporting that ...
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