Questions specific to the CentOS Linux distribution. Use this tag if your question relates to how the CentOS distribution affects your problem; do not use it if you just happen to be using CentOS and your question is about a specific configuration detail or syntax.

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4
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0answers
37 views

Owner can't read /proc/$pid/io

On CentOS 7, I am trying to debug an issue where the nginx amplify agent cannot read /proc/$pid/io even though it is owned by the proper user. One of the nginx worker processes right now is pid 5693: ...
4
votes
0answers
116 views

TC (Traffic Control) to control bandwidth

I'm having an issue with a bandwidth script that I've been using for a while to limit the outgoing bandwidth on a port. It worked fine at the beginning until I wanted to change the outgoing port ...
4
votes
0answers
157 views

pppd issue over serial cable

I'm trying to set up a ppp connection between 2 computers via serial cable, to enable TCP/IP over serial. Computer1 -> USB-Serial Converter -> Serial Cable -> Serial port of Computer 2 On computer ...
4
votes
0answers
523 views

Centos 7 boot up with custom kernel problem

I have installed centos 7 on virtualbox machine which has kernel-3.10.0-123.20.1.el7.x86_64. I am trying to build Linux kernel from kernel sources. I downloaded the kernel source files from: http://...
4
votes
0answers
885 views

Permission problems. Can't retrieve inbox mails from dovecot

I got a VPS server at a webhoster which has CentOS 6.6 as operating system. Because I have multiple domains which are used by various people this server is going to serve multiple roles: nameserver (...
4
votes
0answers
3k views

How can I reset an unknown root password if a file system check interrupts the startup sequence?

This morning I was helping a fellow admin with a crash that occurred on a CentOS 5.8 VM. Earlier in the day, the underlying SAN hosting various VMs experienced an issue and ultimately caused some ...
4
votes
0answers
982 views

How to disable sudo related logging for successful command execution under CentOS/Fedora?

You can disable sudo related log messages via adding something like Defaults:juser !syslog to our sudoers file. That is disabling logging to syslog. But under e.g. CentOS/Fedora there is an auditd ...
4
votes
0answers
722 views

Give domain users permissions on cifs shares?

I am using CentOS 6.5 - users authenticate using winbind, all are domain users except for root. /home is mapped to a cifs share on a windows server in /etc/fstab with this line: \\server\home$ /home ...
4
votes
0answers
290 views

linux io stack analysis

I'm trying to understand the Linux IO stack by analyzing blktrace trace. Below is the trace i captured by executing simple fio sequential write with no Direct IO (5 x 8k request size). 8,16 1 ...
4
votes
0answers
624 views

selinux, dovecot and sieve

I've just started learning to configure SELINUX and this morning on my CentOS 6.4 x64 system, with postfix/dovecot/mysql installed, I woke up to the following selinux issue found 1 alerts in /var/log/...
3
votes
0answers
36 views

Is is possible to override an RPM's service user account during installation?

While doing an installation of an RPM using either rpm or yum is it possible to override the default user account that's typically defined in the RPM .spec file? I'm specifically dealing with an RPM ...
3
votes
0answers
43 views

Can't disable TLSv1 and RC4-SHA

I need to remove TLSv1 and RC4-SHA support in Centos 7. I have these lines in my ssl.conf SSLProtocol +TLSv1.2 +TLSv1.1 -TLSv1 SSLCompression off SSLHonorCipherOrder on SSLCipherSuite "ECDHE-ECDSA-...
3
votes
0answers
89 views

Enable touch screen on CentOS 7

I have CentOS 7 installed as a guest OS inside VirtualBox running in a Windows 8.1 host machine. The host is a notebook computer with a touch screen. The windows host can accept touch screen ...
3
votes
0answers
53 views

Job queueing on a single machine

I have a shiny new server for running simulations on, with a pair of Tesla GPUs and 32 cores, running CentOS 7.2. I'd like for multiple users to be able to submit jobs to the server that get queued up ...
3
votes
0answers
147 views

`yum install` on CentOS 7 states installed size of 578mb, then fails requiring 75+GB more space on /

I have ~10Gb available on /.After running yum install kolab on a new CentOS container yum states the following: Total size: 234 M Installed size: 578 M However, the install then fails with the ...
3
votes
0answers
174 views

Dual Boot Configuration with SSD and HDD

I'm very new to Linux. I have been using Windows/Mac during my whole life, but now I have decided to use Linux. So I'm trying to configure a dual boot system with Windows 10 and CentOS 7. I already ...
3
votes
0answers
84 views

How to get the values for “set root” in menuentry while setting password for GRUB2 on CentOS 7

I need to disable single user mode on my servers running CentOS 7. I read the RedHat documentation on what goes to /etc/grub.d/40_custom and how to encrypt the password and all but one details makes ...
3
votes
0answers
250 views

EXT4 Journaling - Problem

Basically my root (/) ext4 partition keeps being mounted as read-only when I apply internal journaling feature. I understand that this should be default, but today I had been trying to apply external ...
3
votes
0answers
246 views

Expanding root partition CentOS 6 With using fdisk

I am trying to expand the root partition on a VM which is not using LVM and I do not have (nor want to try and create then use) a disk to boot from. As such I followed what I felt was the logical ...
3
votes
0answers
606 views

Install Centos7 with kickstart file fails with “entering emergency mode”

I've created and tested a kickstart file using virtualbox. However, when I try to use the same kickstart file on a different computer, I get "Warning: Could not boot", "Generating "/run/initramfs/...
3
votes
0answers
229 views

Is there way to print the entered password in PAM?

We are using CentOS 6.5. We have a perl script for our automation testing. One of the script login to the user as non-root user and test "su -" command. This test case passes most of the times but ...
3
votes
0answers
527 views

Why don't I hear audio playing from my CentOS 6.5 Vagrant box?

I want to play a wave file from my CentOS 6.5 Vagrant box using aplay and of course I want to hear the sound. This is what I do: > aplay sine.wav Playing WAVE 'sine.wav' : Signed 16 bit Little ...
3
votes
0answers
6k views

Understanding “vncserver -list” with respect to Xvnc processes

I have a pretty standard setup on a Centos 6.5 VM. I've configured VNC sessions to start at boot per CentOS's wiki VNCSERVERS="1:root 2:moe 3:curly" VNCSERVERARGS[1]="-geometry 640x480" ...
3
votes
0answers
8k views

Redhat / Centos 7 Firewalld best practice for pptp or L2TP/IPsec rules

Having a quick look at Centos 7, and though I'd spin up a VPN daemon or 3, but immediately discovered the usual packages aren't yet in the core repositories, so had to dig around and found the ...
3
votes
0answers
252 views

TPM passwordless boot

I'm trying to create device with CentOS6, encrypted disk (with LUKS), TPM module and TrustedGRUB to boot securely and without interaction. I'm following instructions from https://github.com/shpedoikal/...
3
votes
0answers
634 views

iptables hangs at applying rules

I have a set of rules that are supposed to give me the most protection before things like fail2ban and other things are added to the mix. The issue is that although everything checks out in the test, ...
3
votes
0answers
747 views

Microphone not working on Centos 6.5

I have installed CentOS 6.5 on a Dell Insperion with an Intel chip. I first noticed that my microphone is not working on Skype on CentOS although it was working fine with Windows 7 on the same box. ...
3
votes
0answers
66 views

broken filesets after install VLC via RPMFusion

Needed a media player, followed the link on this site Here is the last part of the YUM output; After following the link above, VLC installed and executed fine, but I was left with broken filesets ...
3
votes
0answers
999 views

SCSI Tape drive on ubuntu and centos

On ubuntu 12.10 I have those SCSI drives: [1:0:0:0] cd/dvd TSSTcorp CDDVDW TS-H653N 0208 /dev/sr0 [2:0:0:0] disk Generic USB SD Reader 1.00 /dev/sdb [2:0:0:1] disk Generic ...
3
votes
0answers
191 views

Traffic getting routed through Apache

For some reason, certain outgoing traffic on my server gets routed to the Apache webserver I am running. this problem just started happening. I have the webserver set up to use vhosts, the webserver ...
3
votes
0answers
796 views

How can I tell if no_root_squash is enabled from an NFS client without mounting the share?

Obviously, I can look at /etc/exports on the NFS server-side to see if no_root_squash is enabled, but is there a way I can check this from the NFS client-side without actually mounting the share? ...
3
votes
0answers
605 views

Fedora 14 Xen virtual machine does not detect network

I'm trying to create a para-virt Fedora 14 Xen vm on a host running CentOS 5.5. The VM appears to initially install correctly (the installer finds eth0 and can access the installation media). But when ...
2
votes
0answers
25 views

realm command doesn't work correctly when used in script (CentOS 7)

I try to automate the authentication on CentOS 7 Hosts over my AD with the realm commands. It totally works when I execute the following commands by myself. $ yum -y install realmd oddjob oddjob-...
2
votes
0answers
27 views

How To Permanently Add Source IP to Route Table Entry in CentOS 5.11

I have a multi-homed CentOS 5.11 server in which I have manually changed the default route entry so that packets are sourced from a particular IP (45.32.6.197). How can I make this change permanent ...
2
votes
0answers
38 views

CentOS 7 - Can't mount /var/tmp as bind

I'm working on a freshly installed CentOS7 with LVM. I want to bind mount /var/tmp to /tmp and added the following to /etc/fstab. /tmp /var/tmp none rw,nodev,noexec,nosuid,bind 0 0 ...
2
votes
0answers
38 views

Redhat and Centos servers glibc errors

Please forgive if I am not wording this correctly and my current lack of information, but I am losing my mind trying to figure this out and I am not currently behind the servers in question. I have ...
2
votes
0answers
196 views

rpcbind/nfs fails, failed to create RPC listeners, exiting

My system crashed while a script was running that deploys a pxe boot system (software is called DRBL). Now I can't get rpcbind, nfs, or ypbind to start properly. I'm chasing a series of errors which ...
2
votes
0answers
55 views

CentOS 7: RAID 1 high I/O wait

I am running CentOS 7, with RAID 1 (md) on the hard drives. I have the partitions set as shown below. md0 -> root (sda1, sdb1) md2 -> swap (sda2, sdb2) md3 -> misc (sda3, sdb3) on md3, I ...
2
votes
0answers
106 views

How do I get Consul to work so I can get Docker Overlay to work?

I am running CentOS 7 with Docker. I am trying to install Consul on the Docker server. Consul is unzipped. The binary file works for showing the version. I ran this: echo $CONSUL_RPC_ADDR This ...
2
votes
0answers
53 views

How to set up thousands of VLANs on ISC DHCP-4.1.1-P1 server?

I have been attempting to set up a DHCP server using ISC DHCP-4.1.1-P1 compiled on CentOS 6.7 The idea is to have multiple thousands of VLANs. I have started small. I have no issue doing ifup on ...
2
votes
0answers
262 views

Install CentOS on RAID (manually) on UEFI system

I'm struggling with the manual configuration of a RAID1 + RAID10. I'm trying the procedure on a VM (VirtualBox 5.0.14 r105127) on OSX 11.10.3. The strategy I took is: The complete set of commands I ...
2
votes
0answers
57 views

Why could policy routing on iptables marks applied in FORWARD or OUTPUT chains be inconsistent?

I am routing HTTPS connections down a SSH tunnel (-w) using iptables marks and iproute2 rules, the reasons I need to do it this way are contrived, to say the least, so most alternate solutions may not ...
2
votes
0answers
48 views

Failed to authenticate via ssh.Centos

yesterday I was trying to authenticate via ssh "ssh demo" and return me the following error. ssh: connect to host ip port 7221: Connection refused If you need more information I will provide it ...
2
votes
0answers
127 views

Lost space in LVM

LVM Hey. First of all I want to say excuse me for my bad English. I a problem after installing CentOS 7 with LVM. Some space lost after problem with LVM configuration. I tried to add some logical ...
2
votes
0answers
27 views

lshw HWPath priority — how to determine

I have a project here at work where I'm attempting to definitively map ethernet MAC addresses to physical ports (IE card 1 port 0 is eth0 (mac xx:xx:xx:xx:xx:xx) and a non-technical operator can look ...
2
votes
0answers
45 views

how to build kernel-tools-4.2.xx.rpm and kernel-ltools-libs-4.2.xx.rpm

I am trying to upgrade Centos-7 kernel (kernel-3.10) to (Kernel-4.2.6) and for that I downloaded kernel from kernel.org and create rpm for the custom configuration (arch x86_64)using "make rpm". ...
2
votes
0answers
244 views

CentOS 7 system wide display configuration

I have two displays, one connected via DVI and one via HDMI. I installed CentOS 7, which thinks (like every linux I've tried so far), that the one connected via DVI is the primary display and it's on ...
2
votes
0answers
183 views

NFS mounting options rsize and wsize can't be specified in /etc/fstab

As the Title, the options rsize and wsize can not be specified on Centos7(3.10.0-123.el7.x86_64) cat /etc/fstab: 192.168.11.1:/linux_nfs_share /mnt/nfs01 nfs intr,rw,bg,hard,vers=3,...
2
votes
0answers
48 views

Unable to insert records on sqlite on a Linux environment

I tested a simple Php program using Sqlite3 instead of mySQL on my own computer and it works fine. What the program does is simple insert of record into a certain table. Now, when I try to do that on ...
2
votes
0answers
329 views

How to install man pages in CentOS 6.x minimal for all previously installed packages?

I ran into an issue to where man pages were missing from a CentOS 6.x minimal system (this is normal). I installed the man subsystem and then noticed the man pages were still missing for select ...