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19
Jun

Add self created CA to Zimbra keystore database for External secure LDAP/LDAPS/TLS

When using Zimbra with external LDAP, you may need to use secure LDAP or TLS. Zimbra uses java keytool to import the self created Certificate Authority.

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10
Jun

mysqlbinlog usage with Percona XtraDB Cluster (PXC) on Percona 5.5.37

I needed to investigate a mysql replication issue within Percona XtraDB Cluster on Percona/MySQL 5.5.37. /var/lib/mysql/GRA_*log files are created whenever a replication issue arises. You can use mysqlbinlog to shed some light on the issue.

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29
May

mimedefang multiplexor "No DNS servers available!" issue

Starting with /etc/resolv.conf and add a working DNS server. After the DNS server is definitely configured, make sure the proper Perl modules are installed.

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13
May

CIDR notation ranges /24 - /29 cheat sheet

Here is a breakdown of the slash 24 to slash 29 ranges of IP's. Among other things. these are particularly handy for determining the IP's you can use from a given ISP.
/24 - 0-255
/25 - 0-127 128-255
/26 - 0-63 64-127 128-191 192-255
/27 - 0-31 32-63 64-95 96-127 128-159 160-191 192-223 224-255
/28 - 0-15 16-31 32-47 48-63 64-79 80-95 96-111 112-127 128-143 144-159 160-175 176-191 192-207 208-223 224-239 240-255

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28
Apr

iscsiadm cheat sheet

iscsiadm cheat sheet for Centos 5/6. Login to Single Target, Logout of all targets, Login to all targets found with discovery, Discover targets associated with an IP Address.

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19
Mar

SSH Agent Issue - Could not open a connection to your authentication agent

In order to add a key to your ssh-agent, you need to load the agent first via eval

eval `ssh-agent -s`

After this just run ssh-add and you're set.

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04
Mar
Increase RAM usable by Couchbase Server

Increase RAM usable by Couchbase Server

Couchbase is a caching system that is scalable across many clustered nodes. In the event that your buckets need more RAM, you need to ultimately rmeove the exisiting bucket and increase the couchbase servers total RAM.

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04
Mar
Spacewalk 2.1 Released - Images / Screenshots

Spacewalk 2.1 Released - Images / Screenshots

Spacewalk 2.1 was released today. It includes a new WebUI that should simplify the use of Spacewalk. I feel it looks a little better but does not provide enough increase in functionality.

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19
Dec

Nagios Client NRPE: check_mailq - CRITICAL: Error code 78 returned from /usr/bin/mailq

check_mailq was not working properly. tailing the /var/log/maillog tells me that the /var/spool/mqueue folder is not readable by anyone but root. I made it able to be read by any process running on the system.

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19
Dec

Nagios Client NRPE: check_smtp CRITICAL - Socket timeout after 10 seconds

My nagios client was having issues after a few package updates. About 10 services would report properly for NRPE, except for check_smtp. After lots of checking around the net, the answer was in the /var/log/maillog.

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12
Dec

pgtune for spacewalk server

My Spacewalk 2.0 Server has been working just fine, aside from viewing the systems all at once. The issue appears to be hanging SELECT queries that will idle for about 30 seconds while the systems are being organized into a list(aka just clicking "All Systems" in WebUI). I wanted to give a good read and read/write test because most of the problem is while doing reads. The read write is just for good measure. Appears to be about 10x faster in read only scenario.

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06
Dec

TLS for Sendmail SMTP

I grabbed this article from "netguy.org". As he states, it's hard to get a correct writeup.
http://www.netguy.org/wordpress/?p=299

1. Install openssl-perl:
yum -y install openssl-perl

2. You need to edit the CA.pl file. This was a common area of errors since the instructions for the edit were WRONG. Rather than screwing around with diff files, you just need to make the following changes (copying the existing /etc/pki/tls/misc/CA.pl to /etc/pki/tls/misc/CA1.pl)

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07
Nov

Mount CDROM in ESXi Shell 5.0,5.1,5.5 - Super Micro PDSBM LN2+

I needed to mount a CDROM drive in order to grab older NIC drivers for my SuperMicro PDSBM-LN2+ Motherboard. It has 2 Intel 82573L Gigabit Ethernet Controllers onboard. VMware stopped support for these as of ESXi 5.0. This requires using esxcli software install vib commands in order to roll back the VMware driver bootbank to an older VIB for the Intel e1000e NIC driver. Given that my system has two onboard NICs and no room for expansion, I cannot mount anything over the network to grab the drivers. A chicken and egg scenario. CDROM it is!

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29
Oct

Using 2+ types of bonds on a Centos 5/6 machine

In a previous posting, I laid out the configuration for a single bond on a centos5/6 machine. This configuration needs to change to accomodate multiple network bonds, especially when using two different modes for the bonds. If you do not change the layout and simply add more lines to the /etc/modprobe.d/bonding.conf config file, you will get the same mode applied to both bond interfaces.

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02
Oct
Bacula - Cannot backup Director SQL Catalog

Bacula - Cannot backup Director SQL Catalog

You receive BeforeJob: Can't find your catalog (MyCatalog) in director configuration on your Bacula Director backing up it's SQL Catalog

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30
Sep

Nagios Client NRPE: Unable to read output

On a CentOS 6 machine, you may need to install a few packages in order for nrpe to properly execute remote commands.
Issue:

NRPE: Unable to read output

Run a command that utilizes the local NRPE

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18
Sep

Add self signed CA to Java keystore for TLS/SSL

If you create your own Certificate Authority, you face the hassle of trusting the certificates for authentication. The Java keystore requires a manual import of your CA.

Locate the keytool for your instance of jre

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18
Sep

Replace or Remove a line of text with sed

Replace or Remove a line from a text file using sed. This is helpful when running a script or program that needs to manipulate a file rather that echoing it to the end.

NOTE: Using sed -i over a symlink will replace the symlink with the actual file -- thanks to mxs57 as noted in comments

Replace a line with sed

Usage: sed -i 's/*old line of text*/*new line of text*/g' */config/file/location*

Example: disabling SELinux on a CentOS 5/6 system from the command line:

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08
Sep
Migrate Spacewalk Server with Postgres DB

Migrate Spacewalk Server with Postgres DB

Here is a way to migrate your existing Spacewalk installation to a new server using the postgres dump and import tools. A lot of the setup time for a multi distro spacewalk server is in the repository adding and syncing. This will recreate the repo entries and match them with your software channels. The data sync for /var/satellite will occur shortly after. You can also use this as a procedure to backup and restore your postgres DB with spacewalk.

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08
Sep
Nagios Plugin: Check pfSense gMirror status

Nagios Plugin: Check pfSense gMirror status

Grab the status of your gmirror and report it back to Nagios. This plugin runs in a standard shell as the bourne again shell is not present in pfsense.
Download Plugin : Click here
Published to Nagios Exchange : Click here






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