CentOS is a Linux distribution standing for "Community ENTerprise Operating System" and is a rebuild of "Red Hat Enterprise Linux" (RHEL). The "CentOS6" tag refers to versions 6.x of CentOS.

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3
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2answers
678 views

TCP Messages Merged?

I have an application that sends 100 of 186-byte (excluding headers) TCP messages back to back without gap from host A to host B. I ran tcpdump to capture the packets on host A (where the sender is), ...
1
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2answers
44 views

How to find out who is sending email

I have a server which doesn't have much activity. Today, suddenly server load went higher than 12 which compared to its normal value(0.5) is way too high. I checked and found out that postfix is being ...
0
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1answer
43 views

Linux: How to configure TCP wrappers in /etc/hosts.allow for manually started processes?

An internal server in the company I work for has been compromised and I would like to harden CentOS machines in the organization in order to avoid any future incidents so I've been reading about ...
1
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2answers
41 views

Passing argument in a .py script for nrpe plugin

Machine A = nagios master, Machine B = edge machine. In machine A's host.cfg I have: define command { command_name check_tok command_line $USER1$/check_nrpe -H $HOSTADDRESS$ ...
1
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1answer
51 views

Linux: tftp not working, transfer timed out, what could be the reason?

I have a server which runs cobbler and tftp server. My task is to configure a read-write tftp server. tftp is configured through xinetd and the configuration file looks like so: service tftp { ...
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1answer
24 views

CentOS 6.5 installation [closed]

I have installed CentOS 6.5 today in one of the tower servers I have. Actually the screen went blank while installing and before I could select the options like Server/Desktop, the system ...
0
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0answers
45 views

HDP installation using ambari failing on CentOS 6.7

I am getting following error while installing HDP using ambari. Couldn't make out where the error lies,as error itself is not very clear. ========================== Creating target directory... ...
1
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3answers
137 views

Is there a linux monitoring utility for Dell PERC H700?

I'm looking for a utility to monitor my RAID 5 setup, the card is a Dell PERC H700 with the following chipset: [root@example.net ~]# lspci -v|grep LSI 03:00.0 RAID bus controller: LSI Logic / Symbios ...
0
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0answers
18 views

compiling php for apache

We are planning on upgrading Postgresql on one of our RHEL5 servers to solve a bug and wanted to upgrade php at the same time as it is something we have been wanting to do for a while. I have been ...
0
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0answers
54 views

PHP mail with domain in body

Running the following code snippet does not work. The email is never received. Note that I am using dummy values for email and domain. $to = "email@domain.com"; $subject = 'Mail Test'; $headers = ...
1
vote
1answer
77 views

Logrotate running according to cron, but logs are not rotated

I run logrotate through cron with the script [alex@leia ~]$ cat /etc/cron.daily/logrotate #!/bin/sh /usr/sbin/logrotate /etc/logrotate.conf >/dev/null EXITVALUE=$? if [ $EXITVALUE != 0 ]; then ...
1
vote
1answer
91 views

php is not working with apache after upgrading from 5.3.3 to 5.6

I have a vps with bigrock which had php version 5.3.3 installed. I have recently upgraded php to version 5.6 because some php functions were not working. Now after removing old php and installing ...
0
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1answer
67 views

Issue when trying to run command “YUM Update” Cannot retrieve repository metadata (repomd.xml)

I'm trying to run the update command with yum: yum update I get the follwing message: [root@commerce-dbs-tes-1 ~]# yum update Loaded plugins: fastestmirror Setting up Update Process Loading mirror ...
0
votes
1answer
29 views

What is simple way to ensure that HTTP request with some specific header come only from a specific IP only?

My web application run on Centos6. I want to protect my application. I want to ensure that HTTP request with some specific header come only from a specific IP only. (The header include a user name ...
0
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0answers
30 views

Bandwidth throttling

i am trying to limit download speed on my server only downloads i tried to use wondershaper and trickle but they both mess up with my upload speed tried everything to fix it but no success so is ...
1
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0answers
117 views

curl: (1) Protocol “https” not supported or disabled in libcurl

I've a CentOS6 vps on which O trying to access https url through curl it gives not supported error # curl https://google.com curl: (1) Protocol "https" not supported or disabled in libcurl Anyone ...
0
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0answers
37 views

Trouble with “Keyboard Failure” on Dell PowerEdge R410

I own some Dell PowerEdge Servers. One of these servers is a R410 which has some problems at the moment. I have already sent the server in the datacenter and tried to make a remote installation via ...
1
vote
1answer
51 views

Squid Proxy timing out on Public Interface - Packets getting lost on port 3128

Partial Solution Turns out that traffic on port 3128 was getting lost on the way to my VPS. I am not sure if this is Linode blocking this port, or if it is something in the between. (I have used this ...
0
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0answers
45 views

Could not retrieve mirrorlist in centos

i am try to install mysql repos in centos code is yum install mysql-server mysql Loaded plugins: fastestmirror, priorities, refresh-packagekit, remove-with-leaves, security Loading mirror speeds from ...
0
votes
1answer
66 views

CentOS6.7 vsftpd 530 Permissions Denied

I'm running CentOS 6.7 and I'm trying to successfully establish an FTP connection using vsftpd. Status: Connection established, waiting for welcome message... Response: 220 (vsFTPd 2.2.2) ...
3
votes
2answers
391 views

Redis: Error moving temp DB file on the final destination: Operation not permitted

I have a nodeBB install which relies on Redis as the data store. Its just a test install at the moment while I iron out any problems. The Redis instance stayed up for a few days but then fell over ...
-5
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1answer
46 views

How to increase the size of the root directory in centos 6

how i can increase the size of the root directory .i face some problem of cache of my sql. result of command df -h # df -h Filesystem Size Used Avail Use% Mounted on ...
-1
votes
1answer
72 views

how to resolve nginx 403 error on centos 6

I have installed Centos 6.7 on my virtual box along with Gitlab. I set up gitlab to listen on port 8081. Then I set up nginx to listen on port 80. However after googling for hours and tried some ...
32
votes
2answers
4k views

Why is my bare-metal 16x 2.93GHz cores computer performing poorer than a VPS with 4x 2.5GHz cores?

I have a written a piece of multi-threaded software that does a bunch of simulations a day. This is a very CPU-intensive task, and I have been running this program on cloud services, usually on ...
0
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1answer
36 views

Cannot update with yum - Couldn't resolve host

I have two issues on my bare KVM server, running CentOS 6.7 x86_64 Whenever I try yum update, I get a PYCURL ERROR 6 - Couldn't resolve host 'mirrorlist.centos.org. Configuration in ...
1
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1answer
82 views

Why can't I completely remove myqsl from my CentOS 6 machine?

When I hit the command yum remove mysql I get the following error: Loaded plugins: fastestmirror Setting up Remove Process No Match for argument: mysql Error: File contains no section headers. file: ...
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0answers
15 views

Standalone VM on CentOS KDC Kerberos 5 Server autentication error

After installed and configured the kerberos 5 server on a CentOS 6.7 virtual machine. I tried to authenticate my principal admin and got this error below, I don't understand why the error as it looks ...
0
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0answers
41 views

Apache mod-security - Deny access from IP addresses listed in a blacklist file

I want to deny access from IP addresses listed in a blacklist file (not realy matters, but the file is /etc/csf/csf.deny). This is my custom rule (at the moment..): SecRule REQUEST_URI ...
0
votes
3answers
96 views

How to transfer 6 TB files using SCP?

I have 2 Linux Centos Servers. The First one is 6.7 and the second one is 7. How can I transfer all files and folders from /home/sv1/public_html from server 1 to /home/sv2/public_html in server 2 ? ...
-1
votes
1answer
39 views

pidof service doesn't exist

I am trying to set init.d script for some service - let it be uptime that is located in /usr/bin/uptime. Here is my script: #!/bin/bash # description: read service #Source function library . ...
1
vote
1answer
92 views

daemon function not found in CentOS 6.6

I am trying to set init.d script for some service - let it be less Here is my script: #!/bin/bash -xv # description: read service #Source function library if [ -x /etc/rc.d/init.d/functions ];then . ...
1
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1answer
55 views

MySQL Access Denied error from nodejs application running on port 4567

I can connect to a mysql database from the command line on centos 6.7: mysql -u root -h 127.0.0.1 --protocol=TCP -p; also: mysql -u root -h localhost --protocol=TCP -p; But if I connect from ...
-3
votes
2answers
96 views

OpenVPN Client alongside Apache HTTPD

What is the best way to set OpenVPN Connect on the same server where Apache HTTP Deeamon is running. I have multiple domains hosted on that server and I want to configure OpenVPN on vpn.example.com ...
0
votes
1answer
23 views

ProFTPD. Can upload only in root directory, but it is failed when upload in subdirectories

I can retrieve files but cannot edit and upload. However, I can upload files and directories to root directory. Here I found a solution, but I have UIDs and GUIDs that match linux users. proftpd ...
0
votes
1answer
61 views

ldap_modify: Insufficient access (50) for cn=config as -H ldapi:/// -Y EXTERNAL

I'm setting up a second LDAP server. I've converted a slapd.conf to a slapd.d database using slaptest. I'm trying to apply this LDIF: # cat loglevel.ldif dn: cn=config changetype:modify replace: ...
1
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2answers
52 views

CentOS 6, 2 NICs, 1 gateway, 1 NIC doesn't work right

I have a CentOS 6 install that had 1 NIC, eth0, working fine I added another NIC, eth1. Both NICs are on the same switch, and same LAN. I copied ifcfg-eth0 to ifcfg-eth1, and then simply changed ...
1
vote
1answer
19 views

How can I determine if a package was built from source?

I am trying to determine if httpd is from the rpm or a custom build. httpd -v returns Server version: Apache/2.2.15 (Unix) Server built: Mar 3 2015 12:06:14
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0answers
56 views

Unusually high dentry cache usage leads to PHP performance degradation

We have lots of servers serving lots of requests with apache and php accessing remote memcacheds. But we are experiencing degradation from php side accessing memcached and obtaining lots of memcached ...
0
votes
1answer
86 views

Spamassassin error: spamd.sock does not exist

I am following a guide from arstechnica to install an email server on my web server. I'm not using Ubuntu as stated in the tutorial but CentOS 6. ...
0
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0answers
25 views

How does changing hugetlb_shm_group without a reboot effect running processes?

On CentOS6 how does changing the group id in hugetlb_shm_group and applying the change with sysctl -p effect a running process that currently is using hugepages but will not be allowed to after the ...
0
votes
1answer
84 views

How do I troubleshoot slow NIC on R610 Dell?

I recently set up 2 new R610 servers that I purchased. Summary: Both servers 100% same hardware Both installed with Centos 6.7 64bit Tested multiple switch ports, same slowness issue. Both same full ...
0
votes
0answers
19 views

Disable USB 3.0 per boot

CentOS 6.X does not support the option to boot off of a live USB. The issue is that not always am I able to disable the 3.0 port in BIOS. Is there any way of configuring CentOS to only use USB 3.0 on ...
5
votes
2answers
280 views

NTP: How to establish redundant solution for NTP servers?

In my company's infrastructure there are 5 data centers in remote locations. In each remote location, there's a pair of servers which hold DNS and NTP services and are configured on each one of the ...
0
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0answers
35 views

Identical VMs behave differently

I have 2 Centos 6.7 OpenVZ VPS'. I have copied the entire disk image from the first one (server1) to the second one (server2). Now I have a couple of issues with server1 that I don't have with ...
2
votes
1answer
45 views

Find source of outgoing traffic to specific UDP port [duplicate]

Since a few days ago I've been observing some strange recurrent outgoing UDP traffic from my server on port 24441 but since it's not constant, I cannot seem to find what's causing it. All I can see ...
0
votes
1answer
505 views

Install httpd24, php56 and php70 as SCL is not working with error “file not found”

Let's start saying that I have read this, this and this at Remi Blog since the question it related to those repositories. The blog entries is not helping me at all or I am missing something here but I ...
0
votes
1answer
50 views

How to allow connections in zimbra/mail client?

I installed a Zimbra server into CentOS 6, enter the admin panel via web HTTPS over port 7071, the problem is I can not access the web mail client (port 445), I can only access via localhost. I ...
0
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0answers
32 views

Quantum Scalar i80 - I see the tape drive, but not changer

I have a Quantum Scalar i80 connected via SAS to a CentOS 6 server. When I look in /proc/scsi/scsi, I see the tape drive, but I don't see the changer. From /proc/scsi/scsi: Host: scsi8 Channel: 00 ...
-1
votes
1answer
32 views

ip tables, block all traffic to a specific ip, unless it comes from a specific ip

Here's the situation. I have multiple Apache vhosts listening on port 443 on different IPs, on the same network interface. I would like to only allow a certain IP to access one of those vhosts. In ...
1
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1answer
45 views

Accept all mail for a domain (from everywhere), forward mail for selected recipients to specific addresses, relay all else to a specific host

What I want to do is set up a sendmail server that accepts mail from everyone to a particular domain (say, example.com), then for a list of defined recipients sends that mail onto specified ...