Linux is the generic term for a UNIX-like open source operating system based on the Linux kernel.

learn more… | top users | synonyms (1)

-2
votes
1answer
34 views

Linux Server: Too Many Open Files

I have an application running on Linux Server. But server suddenly stopped responding but when I ping from other machine to server it allowed to ping but was not allowing to login into the server. Not ...
0
votes
1answer
24 views

Redis memory usage impact on performance

While performing health checks of a Redis 2.8.19 setup running on an 30GB Ubuntu Server 14.04 LTS, I noticed that Linux memory usage was split as follows: Used memory : 10GB Cached Memory : 10GB ...
0
votes
1answer
40 views

Centos 6.6 : Which java is selected when I run a JAR/WAR file without using java -jar command? [on hold]

On a Centos 6.6 server, how can I choose which java should be selected when I run an executable JAR or WAR file without using the "java -jar" command. I mean, I'd like to execute it with a ...
1
vote
2answers
45 views

Is there a reliable way to detect OS of the network hosts from linux workstation?

How to detect OS of running computers on the network. We use linux. I want to write wrapper on the python, which will periodically scan network and write results to google spreadsheet. I tried nmap ...
-2
votes
1answer
51 views

Can't Bind IP Address To Machine [on hold]

I have the following IPs but I can't bind them to my machine I am getting errors. Here are the IPs I own. 2607:5300:60:1234::/64 - Came with server 158.69.123.123/29 - ...
0
votes
0answers
11 views

Update Fedora VM Behind Firewall

Let's say I'm living behind a rather annoying, rather restrictive firewall. To the point that Fedora cannot update (and only machines with a graphical browser will function due to login portal). The ...
1
vote
2answers
21 views

Transfer whole Linux system and grub settings to 2nd drive?

I have system partition on /dev/xvda1 (slow disk) and just added SSD attached as /dev/xvdb. How to fully transfer Linux system to /dev/xvdb and retire /dev/xvda1 without using the console? Transfer ...
0
votes
0answers
9 views

Superloader3 and IBM ServRAID-7K

I have a new to me Quantum Superloader3, LTO-4 SCSI Tape library. I have it connected to my IBM X346's External Scsi connection. My system see the tapes but it does not see the MediaChanger's ...
0
votes
1answer
15 views

Compile Node with GCC v4.9.2

I can't seem to be able to compile Node.js on CentOS 6.6 (64 bits) GCC v4.9.2 $ ./configure Node.js configure error: No acceptable C compiler found! Please make sure you have a C compiler ...
2
votes
1answer
38 views

Server not sending ICMP echo reply

I'm having a weird problem with a CentOS 6.6 machine. It is a server running KVM and a few guest VMs using a bridge interface. Basically, my issue is this: The VMs on this host have no network ...
0
votes
1answer
14 views

Multiple Puppet classes need to access a resource and append a value to it, so another class can iterate through it after other classes are evaluated

I'm relatively new to Puppet and have recently inherited a very large infrastructure (Puppet 3.6 on a number of RHEL 6 machines). My Puppet infrastructure looks a bit like this: I have ...
1
vote
1answer
22 views

Simplest infinite script exec without upstart

I've got a CentOS 5.11 box that I have to work with for now--in a production env where I can't really push it to CentOS 6, at least for awhile. I have to be low-impact on this project, can't mess up ...
0
votes
1answer
87 views
+50

Randomize destination port for *every* packet with iptables

There is a program at server side listens on port 3333, and a dedicated client box which sends and receives packet to the server, I'd like to setup a set of iptables rules, make every packet ...
0
votes
0answers
6 views

Setting attributes are not allowed by user while user_xattr mount option is present

/dev/mapper/vg-home on /home type ext4 (rw,relatime,user_xattr,barrier=1,data=ordered) When I try to set attributes with chattr +a +i etc on a file as a user I get back: chattr: Operation not ...
3
votes
1answer
63 views

Linux: Why does the CPU frequency fluctuate when using the performance governor?

I'm using a Debian 8 amd64 machine for benchmarking. During experimentation, I would like the CPU to operate at a fixed frequency (preferably the maximum possible). This will rule out the CPU clock ...
1
vote
1answer
44 views

Linux mysql server will not start, or restart

Intro Im running MariaDB and Apache on my linux machine and today I ran into some problems. I connect to the server via SSH and here are some of the issues Im facing. I have absolutely no idea what ...
3
votes
3answers
255 views

How to SSH after remotely restarting Redhat and enter recovery mode

I need to enter recovery mode of my redhat box which is running remotely on a virtual machine. OS: RedHat 5 64-bit Enterprise Edition I am logged into the box using SSH. I can restart using the ...
1
vote
1answer
37 views

Disk cache impaction on linux df result

I am having a problem in which casing the df results unreliable. I'm using the xfs files system on sles 11 sp3. Basically there is a big difference (a few GBs) between the free size before and after I ...
0
votes
0answers
25 views

How to create several directories in linux using full character set?

I would like to create several thousand directories on ubuntu per command line. Using mkdir {000..999} does create 1.000 directories name 001, 002 etc. How do I create directories using the entire ...
2
votes
5answers
101 views

How to access web page via terminal?

I am testing an Apache server. Normally I open x.x.x.x/directory/index.php in Firefox, then read the httpd/error_logs and troubleshoot. My question is, what if I don’t have a Web browser (e.g., ...
-1
votes
0answers
15 views

Linux mem kernel option caps at 12GB? [migrated]

When I set the mem=16G kernel option on a 14GB RAM machine, free -m reports 12GB of free memory. If I try mem=16G on a 7GB RAM machine, it doesn't change at all. Is this a bug, or is there a way ...
-1
votes
2answers
48 views

Create 2 DNS names for 2 domains on one static IP - Ubuntu

I have VPS Ubuntu 15.04 and there I have configured DNS for one of my external domains. This is sample of configuration at '/etc/bind/named.conf.local': zone "test.com" { type master; ...
0
votes
0answers
17 views

General matter of stateful iptables

I made a set of stateful iptables rules which only handle accepted traffic (More or less). The workflow can be seen in the image below. My questions are: Is it a good idea to drop INVALID state or ...
2
votes
0answers
15 views

Varnish failing intermittently for no obvious reason

For the last few years we have been running Varnish as a cache and load balancer in front of several apache servers serving several thousand websites. We also use monit to ensure that if varnish ...
0
votes
0answers
34 views

A traffic generator for generating real traffic in mininet [closed]

I am using mininet and I want to broadcast a real traffic to my custom topology in mininet. so I am looking for a traffic generator with these 2 specifications: 1- The Inter-departure time for flows ...
0
votes
0answers
30 views

Debian Openvpn port closed

Newbie in linux! there is already similar questions are asked here, but the solutions are not working for me. can somebody help me with this issue: I have been installed openvpn server on debian 8.1 ...
0
votes
1answer
14 views

NixOS reproducible users and packages?

I'm new to NixOS and trying to learn its concepts. One of the reasons I'm excited about it is I'm hoping it will be able to give me a reproducible system configuration, similar to using Ansible for ...
0
votes
0answers
20 views

Terminal piping misunderestanding

Folks I have a few questions around this command: echo 'cat //item/*[local-name()="id"]/text()' | xmllint --shell test.xml | sed '1 d;$ d;/^ -------$/ d' | sort | uniq --repeated I thought command ...
-3
votes
2answers
60 views

What's the best method to achieve full redundancy in a dedicated server? [on hold]

I've been reading about full redundancy to achieve almost if not 100% uptime for your mission critical applications (handling financial data) running in a dedicated server, but I still can't wrap my ...
-4
votes
0answers
21 views

using samba 4 for implementing policies gpmc comes empty with no policies at all [on hold]

what i want to do is to add roaming profile for every user on my server, ok until here but the gpmc.msc comes empty without policies at all or creating a forest have only the basic things no computer ...
0
votes
3answers
31 views

iptables “host/network not found”

If I add this line to my iptables: -A INPUT -s /32 -i tcp -p tcp -m tcp --dport 22 -j DROP I get the error: iptables-restore v1.4.14: host/network' not found` When running: sudo iptables-restore ...
-1
votes
0answers
15 views

Server Monitoring with Antivirus and Intrusion Detection [closed]

I currently in the process of hardening my Linux boxes and I'm looking for a solution that combines Server Monitoring(CPU utilization, RAM, swap space, pinging, etc) Intrusion Detection(something ...
1
vote
0answers
27 views

How does EC2 signal a reboot to an HVM instance?

What is the exact signal being sent? How can the instance (Linux in this case) handle it?
0
votes
0answers
57 views

Linux disk moved on a different server won't boot

I have a server HP Proliant DL120 G6, with an installed and working Ubuntu 14.04. The partitioning is reported below. Now, if I move the disks on a very similar HP Proliant DL120 G5, in the same ...
0
votes
0answers
12 views

Linux GRE tunnel [closed]

Is it possible to setup a GRE tunnel without IPTables? My situation - Server with 5 additional IPs (6 IPs in total, 5 alias IPs;IPv4) with 10Gbps DDoS protection Another server with 2 IPs (one ...
-1
votes
2answers
57 views

Reject email if “rcpt to” does not match relay_domain - Postfix

My mail server currently shows up in mxtoolbox as Open Relay. Objective: Allow SMTP connection only when RCPT TO: says example.com What changes should I make in it so that, it would reject the ...
-1
votes
0answers
22 views

Create a new routing table [closed]

I want to route packets from a specific ip address through a specific device. I am going to do something like in ...
4
votes
0answers
29 views
+250

Kerberos service login only possible for 30 minutes after running ktpass.exe

I'm trying to Kerberize an Apache-server, and allow the created server principal to sign on to the Active Directory. I've followed one of the numerous tutorials available online, and it seems to work ...
6
votes
1answer
249 views

How do I tell how close I'm getting to somaxconn?

The sysctl option net.core.somaxconn defaults to 128 (on our systems) but can be raised. What exactly is this limit measuring and capping? How do I find out how close I am to the limit? Context: I ...
1
vote
2answers
34 views

Ansible conditional statement based on other roles?

I've got the following scenario with an Ansible deployment: hostX has the role common-mta and a few other roles hostY has the role common-mta as well as the role package-postfix The common-mta ...
2
votes
1answer
22 views

Can idle NFS mounts on several clients impact performance

We had a NFS server at work which was working with slight lag. However as more mount points were getting created at several clients(serviced by the same server) we noticed the performance coming to a ...
2
votes
1answer
26 views

Getting Bonding Status in CentOS 7

In CentOS 6 I had my trusty /proc/net/bonding/bond0 that would give me the following information: [kbrandt@ny-tsdb01: ~] cat /proc/net/bonding/bond0 Ethernet Channel Bonding Driver: v3.7.1 (April 27, ...
3
votes
1answer
28 views

How do I determine the Linux user/group which executes systemd manager jobs?

I am trying to determine which Linux user/group runs systemd jobs so that I can set D-Bus permissions accordingly. When I do this: sudo systemctl start myservice That ultimately calls an ...
0
votes
0answers
20 views

linux virtualization + Qmenu [closed]

Can someone explain what is actually the Qmenu (http://wiki.qemu.org/Main_Page) I need to install on my linux machine ( red-hat )different 4 virtual machines by OpenVZ so How the Qmenu can bring ...
0
votes
0answers
22 views

wpa_supplicant doesn't reach freeradius in 802.1x eap-tls wired

I want to setup a 802.1x EAP-TLS connexion with freeradius, wpa_supplicant and a Cisco Switch My network : supplicant eth0-----f1/1 SWITCH f1/0-----eth1 Freeradius the SWITCH is an emulated Switch ...
-3
votes
0answers
16 views

Tomcat Monitoring and management [closed]

I have been studying the tomcat official document for the enhancement and security of tomcat. Till the time to get to know the errors of the web application we use to study the log files generated by ...
1
vote
3answers
69 views

SSH and security guidelines

I'm trying to set-up an ubuntu server (14.04 LTS) following some security guidelines. One of these guidelines suggests to disable root user and create a new user that works as an administrator using ...
-3
votes
0answers
46 views

Default gateway is not reachable [migrated]

I have a vmware player on which i have installed CentOS 6.5. And on that CentOS 6.5 i have installed lxc and on that lxc i have installed centos 6.3. I am using NAT and bridger as a Network adaptor ...
-1
votes
0answers
20 views

How to configure Postfix to relay mails to remote Mailman server?

I want to setup a postfix server a.example.com on one physical maschine and a postfix/mailman server b.example.com on another maschine. All mail is received by server a.example.com and has to be ...
-7
votes
0answers
35 views

Amazon GeoDNS (Route 53) [closed]

I own a DDoS protection company (StopDoS.xyz) I want to use Amazon's dns to route visitors to the closest location matching their requester ip address location How will this work for DDoS ...