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Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.

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Begin Process info for 21444
Mon Jun 19 13:30:21 UTC 2017
Thread 224 (Thread 0x7f2fe55f1700 (LWP 21454)):
#0  0x000000325fc0b68c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/
#1  0x00007f2ff296e98e in NQConditionWait::Wait() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#2  0x00007f2ff29bbfe8 in NQSemaphore::Acquire() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#3  0x00007f2ff2970389 in NQConditionWaitLIFO::Wait(NQSemaphore&, PerfTimeSnap&) () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#4  0x00007f2ff29704b9 in NQConditionWaitLIFO::Wait() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#5  0x00007f2ff29d7802 in PoolThread::ExecuteUserMain() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#6  0x00007f2ff2998f39 in NQExecutionState::ExecuteSystemMain() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#7  0x00007f2ff29d3f06 in NQThread::ExecuteSystemMain() () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#8  0x00007f2ff29d44ae in NQThread::ThreadMainEntry(void*) () from /u01/app/obiee12c/bi/bifoundation/server/bin/
#9  0x000000325fc07aa1 in start_thread () from /lib64/
#10 0x000000325f4e8bbd in clone () from /lib64/
Thread 223 (Thread 0x7f2fe54f0700 (LWP 21455)):
#0  0x000000325fc0ba5e …
What is SQL Server and how does it work?
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

I have a box that I configured to use MD RAID during the install process for the OS and boot drive. It's this weird /dev/md0p# structure that confuses me.

The installer produced /dev/md0p1 (/boot), /dev/md0p2 (/var/lib/mysql), /dev/md0p3 (/), /dev/md0p4 (extended), /dev/md0p5 (swap). I noticed it did this for all physically installed machines from the CentOS 6 DVD.

How do I increase the size of the /dev/md0p3? I need this root partition to be expanded. I feel like I need to delete the /dev/md0p3, /dev/md0p4, /dev/md0p5 partitions and then create a new one for /dev/md0p3 with the extra space. I don't care for p4 and p5, because they don't contain actual data. I can create them after the fact.

I am confused on the order of deleting partitions and adding the space in respect to /dev/md0. fdisk -l shows the drives /dev/sda, /dev/sdb and then finally /dev/md0 with all of the sub partitions.
Hi ,
I have deployed new nagios server centos 7.3 add host (centos 7) using nrpe but getiing this error " No output on stdout) stderr: connect to address port 5666: No route to host  "
I have linux server and i want to count pdf pages is colored or bw.

i have used imagemagic but it takes serverd down so can you help me with alternative way?
Hello All,

I am in a situation to push database audit XML logs to syslog server. Audit logs are getting generated when Audit_Trail is set to OS. The same is not happening when Audit_Trail is set to XML,EXTENDED. Please advice on this.

SQL> select banner from v$version;

Oracle Database 10g Enterprise Edition Release - Prod
PL/SQL Release - Production
CORE      Production
TNS for Linux: Version - Production
NLSRTL Version - Production

SQL> show parameter audit
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
audit_file_dest                      string      /u01/appldrch/DRCH_DB_audit_lo
audit_sys_operations                 boolean     TRUE
audit_syslog_level                   string      LOCAL1
audit_trail                          string      XML, EXTENDED

[root@appsdr ~]# cat /etc/syslog.conf
local1.warning /var/log/audit.log

Thank You.

John Marshal.A
Hi friends,

I'm in (preemptive !) need for some bootable antivirus rescue disk for offline scanning of Linux systems - preferably a flavour that could be banned onto a bootable USB stick and with good test results ...

Any recommendations ?
Hi Experts,

I want to connect to multiple redhat machines from Windows powershell and retrieve configuration info from redhat systems.

What is the best way to achieve this. ?

I know there is a putty tool to connect to linux systems but is there a way to retrieve info from redhat machines like CPU, memory etc.

I would really appreciate if you could help..

I am a beginner with this, and after configuring JAVA and Wildfly, I get the following error when trying to run :

14:27:33,895 ERROR [] (Controller Boot Thread) WFLYSRV0055: Caught exception during boot: WFLYCTL0085: Failed to parse configuration
        at [wildfly-controller-2.2.0.Final.jar:2.2.0.Final]
        at [wildfly-server-2.2.0.Final.jar:2.2.0.Final]
        at$ [wildfly-controller-2.2.0.Final.jar:2.2.0.Final]
        at [rt.jar:1.8.0_131]
Caused by: com.ctc.wstx.exc.WstxParsingException: Received non-all-whitespace CHARACTERS or CDATA event in nextTag().
 at [row,col {unknown-source}]: [87,9]
        at [woodstox-core-asl-4.4.1.jar:4.4.1]
        at [woodstox-core-asl-4.4.1.jar:4.4.1]
        at [woodstox-core-asl-4.4.1.jar:4.4.1]
        at …
Hi, some time ago I have cloned and installed this project on the VMs where SELinux was disabled
And now I can see this doc , where they say: Security-Enhanced Linux (SELinux) must be enabled on all of the servers before installing OpenShift Origin or the installer will fail.
So my question is how does Openshift play with SELinux? What is the algorithm of this play?
This is using Amazon t2-micro AMI 64-bit linux EC2 instance. I have a gmail email address, thinking of setting up a mail client, with correct credentials so as email can be sending out from this server. I saw a Sendmail daemon is running. I am thinking of sending a tripwire report to my gmail email address, with the cron job command as shown:

/usr/sbin/tripwire -m c | mail -s "Tripwire Report from HOST"

I heard that sendmail client is pretty difficult to setup. How about other mail client, such as postfix, and so on.

Thanks in advance.
Back Up Your Microsoft Windows Server®
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Hi All,

After the filesystem issue on my VCSA v6.5, I suddenly unable to login to the server with the below error:

A server error occurred.
Unable to log in because you do not have permission on any vCenter Server systems connected to this client.
Check the vSphere Client server logs for details.

Open in new window

I can login using administrator@vsphere.local but not anything with AD integrated account.

Here's the chronological order:

-- vCenter server down
-- not pingable.
-- Issues seen in the ESXi host which the vCenter VM is residing on :

2017-06-17T11:07:34.592Z: [scsiCorrelator] 2630366567703us: [] Lost connectivity to storage device naa.6000eb3311ab55e3000000000000040f. Path vmhba37:C0:T9:L0 is down. Affected datastores: "PRODSQL01_Backup"..

-- vCenter VM hangs in the black screen - where it goes into the single user mode.

Reason :
-- The root filesystem has mismatching inodes.

Action taken :
To fix the issue we went ahead and cleaned the filesystem bad blocks.

executed the below commands :
1. Check the filesystems :


2. Run the e2fsck against the filesystem for root

e2fsck /dev/sda3

3. Fix the inodes when asked for it
4. Once process completes, reboot the virtual machine.
What is a quick but definite test to run from the Linux command line to check if dns requests are being hijacked. The test should not require having to change the dns servers for the device that the test is being run from.
This is an attempt to setup clamav on the Amazon t2-micro 64-bit linux server, with 1 gb ram. Initially, the packages were downloaded as follows:

sudo yum install clamav clamav-scanner-sysvinit clamav-update –y

After that, the freshclam.conf was updated as follows:

sudo vi /etc/freshclam.conf

Remark of:

Remove the remarks of:
DatabaseDirectory /var/lib/clamav
UpdateLogFile /var/log/freshclam.log
DatabaseOwner clamupdate

Run the freshclam, and got all the main updates downloaded

Then, update the scan.conf

sudo vi /etc/clamd.d/scan.conf:

Remark of:

Remove the remarks of:
LocalSocket /var/run/clamd.scan/clamd.sock
FixStaleSocket yes
TCPSocket 3310

But this time round, attempt to start the clamd.scan daemon failed. Please see the errors on /var/log/messages as attached.

Look like the RAM is not enough? I heard that we can change to use cron job to replace the daemon, for this low memory system, is that true? or else any resolution?
I had this question after viewing Network issues with Linux Bonding and Cisco 2960-S.

Old, question... but its talking about bonding cisco and linux sides.  I have successfully setup linux bonding (mode 4 - lacp ) with cisco switches ( 4948 ) in the past.  But what i want to do now, i dont know enough about cisco to do so.  I am a devop guy, so networking, especially cisco gear, is a little outside by knowledge base.  

setup some kind of bonding on the cisco side that allows me to first plug a server in, boot it, install from the network, then reconfigure it into a bonding setup.... automatically.

I have a bunch of servers i am trying to automatically deploy.  i want to boot them up with nothing on them, use the ubuntu MAAS (metal as a service ) to install an OS on them, then use ansible to connect to the newly installed server to then create the interface bonds.  At that point, i would then like the cisco switch to use lacp( or some type of similarly useful bonding ).  

The issue is a chicken/egg scenario.  You have to create the port channels on the cisco and add the ports to them and set them for lacp( as far as i know, and why i am asking this ).  On the linux side, you then need to setup bonding and set the mode to 4.  Since i am doing everything automagically using MAAS and ansible ( tested and working ).  It SEEMS i cannot setup the …
Hi,  I'm seeking guidance from team and sort out things out.  I currently hold a Security+ cert that's due to expire in 11/17 and at the same time moving to a new position that requires Linux support on the (desktop) client side.  So my question is, instead of renewing my Security+, study for Linux cert and use it as a CE for my Security+.  I'm required to maintain my security+ cert due to the nature of m y job but I'm interested in adding another cert to my resume.  
What do you guys think and the best place to start and plus study material?
I ordered "Red Hut Enterprise Linux 4 for DUMMIES" BOOK from eBay and it has CD as well.  I've a spare laptop and a desktop and enough resources to install Linux but I need guidance. BTW, I've been a Windows professional for many years and would like to mix things up a bit.
Your thoughts ??
When I set a game to fullscreen, it is not on the main monitor, but half of monitor one and half of monitor two.

Linux Mint 18.1 Cinammon 64bit
Kernel - 4.4.0-79-generic
Nvidia Geforce GTX TI (Driver 375.66) LTS Driver
I5 4460 3.2x4

We are trying to bring up a postfix mail server on an AWS EC2 instance. We have gone through SES but we need to manage our mail server rather than AWS managing it for us.

We already have a domain The next step would be to bring up a EC2 instance and install Postfix on it. I would assume we need an Elastic IP assigned and then map a DNS to it so that is is resolvable. I'm next assuming we need to assign an MX record for Would this generally work if you send email to or are there additional steps like assigning SPF records and DMARC.
We hvae created new policy to check particular vulnerabikity in unix. We have enabled all the required plugins however scan doesnt discovered the host even. So looking what are the other mandatory/ dependent plugins need to enable.
1) Again: my sister is the bookkeeper for the local cemetery.  She's 4th or 5th keeping internment books.   I saw her books and took 15 months and typed them into computer.  They're now legible and easy to search.  
2) She also has maps of the cemetery that are wearing out too.  I used  Inkscape to redraw her maps.  I'm worried I'm trying to push a square peg through a round hole.  Is there a graphics drawing program that I can PROGRAM to use my digital internment book from  step #1 and fill information into the map items?  Pretend you are making papers that say "happy birthday <kid's name here>" and you write a program that adds their names from a list you have.  It doesn't seem inkscape will do this.  Is there a different program than inkscape that can do this?  Linux is preferred but I considered dual booting my machine anyway.  I'll even go so far that I BUY software. :)
Three Reasons Why Backup is Strategic
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I've seen the questions and answers about using /etc/pam.d/system-auth and "auth required inactive=30" ( I also added to /etc/pam.d/gdm), but that seems to depend on lastlog and users logging into the gdm are not tracked in lastlog.

Making the password alone lock isn't enough since I want to lock for smart card login as well.

Do I need to implement a script/cron to track inactivity? Or can pam really take care of this for gdm logins?

Thanks in advance!
I have linux application account and  would like to restrict the user to login directly. I want this account to be under sudoers. users can login and sudo into this account. How do i do that in linux?
HI I have xxx folder within it there are many .cfg files I want to hide just one file ie: ptr.cfg How to do this with proftpd HideFiles ?
Hi guys,

I get this screen tearing through mozilla when playing videos on a shuttle ds81 and a DH110 and i thought i had a fix by using this i am using ubuntu server 16.04

wget - O /usr/share/X11/xorg.conf.d/20-intel.conf f

Any ideas?
how can I create the OpenVAS agent to be installed on a remote system to report scan results back to the main server?
In OpenVAS console under admin/agents you can create an agent but I need to specify a package and signature. Not clear how to get that done and google searches provide no info
Executing(%prep): /bin/sh -e /var/tmp/rpm-tmp.RGaLcw
+ umask 022
+ cd /root/rpmbuild/BUILD
+ export LANG
+ unset DISPLAY
+ cd /root/rpmbuild/BUILD
+ rm -rf centrifydc
+ /bin/tar -xvvf /root/rpmbuild/SOURCES/centrifydc.tar.gz
drwxr-xr-x root/root         0 2017-06-12 09:50 etc/
-rw-r--r-- root/root        45 2017-06-12 09:50 etc/hosts
-rw-r----- root/root        52 2017-06-12 09:50 etc/sudoers
drwxr-xr-x root/root         0 2017-06-12 09:50 etc/centrifydc/
drwxr-xr-x root/root         0 2017-06-12 09:50 etc/centrifydc/ssh/
-rw-r--r-- root/root      1236 2017-06-12 09:50 etc/centrifydc/ssh/banner
-rw------- root/root      3898 2017-06-12 09:50 etc/centrifydc/ssh/sshd_config
-rw-r--r-- root/root      1855 2017-06-12 09:50 etc/centrifydc/passwd.ovr
-rw-r--r-- root/root       500 2017-06-12 09:50 etc/centrifydc/user.ignore
-rw-r--r-- root/root     85799 2017-06-12 09:50 etc/centrifydc/centrifydc.conf
-rw-r--r-- root/root        24 2017-06-12 09:50 etc/resolv.conf
+ cd centrifydc
/var/tmp/rpm-tmp.RGaLcw: line 34: cd: centrifydc: No such file or directory
error: Bad exit status from /var/tmp/rpm-tmp.RGaLcw (%prep)

RPM build errors:
    Bad exit status from /var/tmp/rpm-tmp.RGaLcw (%prep)





Articles & Videos



Linux is a UNIX-like open source operating system with hundreds of distinct distributions, including: Fedora, openSUSE, Ubuntu, Debian, Slackware, Gentoo, CentOS, and Arch Linux. Linux is generally associated with web and database servers, but has become popular in many niche industries and applications.