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Install RabbitMQ in High Availability

In this post we'll install RabbitMQ in High Availability on 3 nodes.  We'll do this to share out the instance with third party applications that need it while providing fault tolerance. We will reference the following post but instead on CentOS 7. So let's get started. HOSTS COMMANDS DESCRIPTION rmq01 / rmq02 / rmq03 CentOS [...]

AWX / Ansible High Availability Configuration on CENTOS 7

AWX / Ansible High Availability Configuration on CENTOS 7 . So we want a highly available and scalable AWX and Ansible cluster solution.  Here's how we'll plan things out: NAME ADDRESS HOSTNAME SERVICES awx01 awx01.nix.mds.xyz AWX, Gluster, Keepalived, HAProxy awx02 awx02.nix.mds.xyz AWX, Gluster, Keepalived, HAProxy awx03 awx03.nix.mds.xyz AWX, Gluster, Keepalived, HAProxy awx-c01 [...]


This is how to get detailed TCP dumps of your network traffic while avoiding your own PuTTY traffic in the output: tcpdump -w trace.dat -s 0 port not 22 tcpdump -r trace.dat -nnvvveXXS > trace.dat.txt Cheers, TK

mount.nfs: mount(2): Permission denied

You're getting this message: [root@mysql01 /]# mount -v nfs03:/n /m mount.nfs: timeout set for Thu Nov  8 23:37:04 2018 mount.nfs: trying text-based options 'vers=4.1,addr=,clientaddr=' mount.nfs: mount(2): No such file or directory mount.nfs: trying text-based options 'addr=' mount.nfs: prog 100003, trying vers=3, prot=6 mount.nfs: trying prog 100003 vers 3 prot TCP port 2049 mount.nfs: prog [...]

Postgres SQL HA Cluster ( Quick Start Guide )

We will be keeping the Postgres SQL HA Cluster configuration / setup very very brief using only the bare essentials to get it up and running. Before we begin, we need to plan things out on our CentOS 7.X servers.  First, fill in this table of what your cluster is supposed to look like when [...]

Forbidden You don’t have permission to access /repos/ on this server.

So you get the following message when installing and configuring your HTTPD server?  Despite the right configuration you still receive the following: Forbidden You don't have permission to access /repos/ on this server.

1765328228 Cannot contact any KDC for realm

When seeing this: krb5_child.log:(Tue May 22 02:06:15 2018) [[sssd[krb5_child[1605]]]] [map_krb5_error] (0×0020): 1657: [-1765328228][Cannot contact any KDC for realm 'MDS.XYZ'] Access denied Using keyboard-interactive authentication. Password: reverse the order of your DNS hosts in /etc/resolv.conf to this: [root@cm-r01dn07 sssd]# cat /etc/resolv.conf search mds.xyz nix.mds.xyz nameserver nameserver nameserver [root@cm-r01dn07 sssd]# from this: [root@cm-r01dn07 sssd]# [...]

sssd krb5_child Key table entry not found

When you get this message: May 21 00:13:31 nfs03.nix.mds.xyz [sssd[krb5_child[1822]]][1822]: Key table entry not found followed by: [[sssd[krb5_child[1752]]]] [k5c_setup_fast] (0×0020): 2628: [-1765328203][Key table entry not found] or similar, dig into the logs further to see this: (Mon May 21 00:13:33 2018) [[sssd[krb5_child[1824]]]] [find_principal_in_keytab] (0×0400): No principal matching host/nfs02.nix.mds.xyz@NIX.MDS.XYZ found in keytab. (Mon May 21 00:13:33 [...]

Saving random seed failed. / No kdump initial ramdisk found. / Failed to run mkdumprd

Kdump doesn't start? [root@mbpc-pc grub]# service kdump restart Memory for crashkernel is not reserved Please reserve memory by passing "crashkernel=X@Y" parameter to the kernel Stopping kdump:                                            [FAILED] No kdump initial ramdisk found.      [...]

NFS reply xid 3844308326 reply ERR 20: Auth Rejected Credentials (client should begin new session)

Getting this? Mounts freezing?  Final verified solution is at the bottom but this can be for any number of reasons.  Keep reading: tcpdump -i eth0 -s 0 -w dump.dat tcpdump -r dump.dat |grep -Ei "psql02|nfs-c01" 02:55:48.731360 IP psql02.nix.mds.xyz.33991 > nfs-c01.nix.mds.xyz.nfs: Flags [P.], seq 1:693, ack 1, win 229, options [nop,nop,TS val 166990 ecr 5681495], length [...]

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