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BIND 9.9.X – How to view BIND Slave Zone files?

August 29, 2017 by @HKw@! | No Comments | Filed in centos, DNS, Linux

If you recently update your BIND server to version 9.9.X, you will noticed that you unable to read slave zone file.

Below is the example of zone file

As per checking on BIND official release notes from ISC, BIND version 9.9.x store Slave Zones file in raw/binary format.

In order to view the content of Slave Zone file, you need to convert “raw” format zone files to “text” format using the named-compilezone utility that comes with BIND. (more…)

CentOS – Existing lock /var/run/yum.pid: another copy is running as pid xxxx.

May 29, 2017 by @HKw@! | No Comments | Filed in centos, Fedora, Linux, RedHat

Error Message “Existing lock /var/run/yum.pid: another copy is running as pid xxxx.”  is a very common error which you might come across in Red Hat Linux distro while trying to run yum command.

As you see the error from above screenshot, it mentioned that yum command is locked by another application. Meaning that someone already run the yum command and the process is running.

To find out which process and user holding the yum lock, just enter following command:-

From the above screenshot, PID 11290 is currently run by root user and holding the yum lock.


It is very easy to solve this issue, first wait the process finished. Second is kill the process ID. Below is the command to kill the PID

kill -9 11290

Now you should able to use yum command.


MacOS Sierra: Unable to negotiate with IP X.X.X.X port 22 no matching host key type found. Their offer: ssh-dss

May 22, 2017 by @HKw@! | No Comments | Filed in centos, Linux, Mac OS X


My latest MacOS X 10.12 release failed to ssh to network devices with the following error:

techkaki-MacBook-Pro:~ techkaki$ ssh root@
Unable to negotiate with port 22: no matching host key type found. Their offer: ssh-dss

Root Cause

OpenSSH Version 7 and above disable DSA key by default.


A) To enable the ssh-dss (DSA) key exchange algorithm  using the HostKeyAlgorithms option:

ssh -o HostKexAlgorithms=+ssh-dss  aimsadm@

B) Enable ssh-dss (DSA) on ssh_config by adding HostkeyAlgorithms +ssh-dss at the end of the ssh_config file.

sudo nano /etc/ssh/ssh_config

Screen Shot 2017-05-22 at 11.54.31 AM

Hope this information will help 🙂

Reference link:-