I just read the news about IBM aquiring Red Hat

What will this will mean for CentOS?

Informix never forget 😉

Creation/Manipulation of tables:

CREATE TABLE tabelle (nummer int, text char(10), time datetime, date date);
DROP table tabelle;
ALTER TABLE table_name MODIFY (name char(100));
ALTER TABLE table_name ADD column_name column-definition;

can be positioned with AFTER/BEFORE

Unloading tables:

unload to '/home/content.csv'
delimiter ';'
SELECT * FROM content

Transactional Stuff:

BEGIN WORK;
ROLLBACK WORK;

Query Time:

SELECT |ALL|DISTINCT|UNIQUE|FIRST 
FROM table (WHERE)
GROUP BY columnname
HAVING COUNT(**)>1
ORDER BY columnname (ASC|DESC), ....
INTO TEMP tablename

WHERE-Clause:

bla (NOT) BETWEEN bla AND 
bla (NOT) IN (List, of, bla)
bla (NOT) LIKE "bla"
bla (NOT) EXISTS 
bla IS (NOT) NULL

to combine multiple selects

UNION

TO_CHAR transformation for query:

SELECT nr FROM numbers WHERE nr MATCHES "38*"
Error 219: Wildcard matching may not be used with non-character types.

SELECT nr FROM numbers WHERE TO_CHAR(nr) MATCHES "38*"

If you want to manipulate DNS-Entries before and without ISP-DNS Resolution you can do it with extra DNS-Server at your site. Best thing would be putting this DNS in DMZ-Zone.

e.g. Youre hosting WebEx and have one Public-URL to connect. Your Internal Clients will always route the traffic via Internet. To avoid this you can override the DNS – Resolving at your ISP with an own DNS. It’s also possible with your own Windows-DNS but… I like Linux 😉

Here I did with Linux, because its free:

Install BIND and configure named.conf

//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
 
options {
        listen-on port 53 { 127.0.0.1; 10.1.10.100; };
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { localhost; 10.1.0.0/16; 10.2.0.0/16; };
        recursion yes;
 
        //dnssec-enable yes;
        //dnssec-validation yes;
        //dnssec-lookaside auto;
 
        /* Path to ISC DLV key */
        //bindkeys-file "/etc/named.iscdlv.key";
 
        //managed-keys-directory "/var/named/dynamic";
 
        forwarders { 8.8.8.8; 8.8.4.4; };
 
};
 
logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};
 
//zone "." IN {
//      type hint;
//      file "named.ca";
//};
 
 
include "/etc/named.rfc1912.zones";

Important parts of config:

Who is allowed to query this DNS?

 allow-query { localhost; 10.1.0.0/16; 10.2.0.0/16; };

Forward-Adresses for DNS-Requests which cannot be handled/resolved by the local DNS

forwarders { 8.8.8.8; 8.8.4.4; };

For your linking your own zones:

include "/etc/named.rfc1912.zones";

If you do changes, dont forget to restart

zone "override.untony.org" IN {
type master;
file "named.override.untony.org";
allow-update { none; };
};

$TTL 86400 @       IN SOA  @       root (                                         2013111501      ; serial                                         1D              ; refresh                                         1H              ; retry                                         1W              ; expire                                         3H )            ; minimum @        IN NS          localhost. @        IN A           194.232.104.3

MRemote NG is in my opinion the best tool for managing your Remote Connections!  (https://mremoteng.org)

Great tool to manage multiple SSH, Telnet, RDP, VNC, HTTP(S), etc

I always forget the order of cronjob timings, so this is a reminder for me

In short:

#/etc/apt/sources.list editing
echo -e "\n# Clonezilla" >> /etc/apt/sources.list

echo "deb http://drbl.sourceforge.net/drbl-core drbl stable" >> /etc/apt/sources.list

# Add GPG-Key
wget http://drbl.sourceforge.net/GPG-KEY-DRBL
apt-key add GPG-KEY-DRBL

#Update Packagelist
apt-get update

#drbl installation
apt-get install -y drbl

#Set up Clonezilla und drbl
drblsrv -i
drblpush -i

Inside of your DHCP you have to reconfigure:

For the neccessary scope.

Option 66 with IP Adress of cloning server

Option 67 with  pxelinux.0

Long(er) Explanation here:

OS Installation

Install an Ubuntu or Debian Server first. Then start with Clonezilla SE Installation. Commands have to be executed by root

sudo -i

Add this Line in your /etc/apt/sources.list

deb http://drbl.sourceforge.net/drbl-core drbl stable

then import the GPG-Key

wget http://drbl.sourceforge.net/GPG-KEY-DRBL
apt-key add GPG-KEY-DRBL

To renew sources do:

 apt-get update

and install dbrl

apt-get install drbl

This should also install every dependencies

Set up Clonezilla

First start with configuring dbrl

drblsrv -i

1. Install Network Boot-Images: If you want to boot from Images, not for installing so i chose „N“
2. Serial Output: I chose „N“
   
3. Operating System update: I chose „N“
4. Kernel for Client: I chose 1

Next step is:

drblpush -i

1. DNS-Domain: choose your local domain
   
2. NIS/YP Domain-Name: not neccessary
3. Präfix for Clienthostname: as you wish eg. clonezilla
   
4. NIC for Internetaccess: mostly eth0
5. Collecting MAC-Adresses: You can choose N
6. Ip-Adress to MAC: Clients do always get the same IPs (like reservations)
7. Start of IP-Adress-Range: eg. 1, First IP is then 192.169.0. 1
   
8. Max Clients: eg. 20, last IP would be 192.169.0. 20
   
9. Diskless Services: Not needed
10. Type of usage: For our scope 1 is enough
11. Where to put the images?
12. You can choose a password for accessing Clonezilla
13. Bootprompt for Clients: N
    

• Create a share on a server
• Install cifs-utils: apt-get install cifs-utils
• Create a folder under /mnt for mounting:
  mkdir /mnt/backup
• Inside of /etc/fstab define the mountpoint:

//backupserver/Linux_Backups   /mnt/backup   cifs    credentials=/etc/cifspw    0       0

• Create /etc/cifspw with credentials für a „mounting-user“

> Ubuntu 12

username=linuxmountpassword=linuxmountpassworddomain=DOMAIN

< Ubuntu 13

username=DOMAIN\linuxmountpassword=linuxmountpassword

• Try via mount -a if mounting works and verify output of df or simply go to /mnt/backup (cd /mnt/backup)
• Create a file called mysqlbackup.sh inside of /usr/sbin and add this content:

#user='root'
#password='youshouldcreateabackupuser'
user=backup
password='password'
for db in 'mysqlshow -u $user -p$password | sed -n -e "s/^| \([^ ]*\)[ ]*|$/\1/p"'  
do mysqldump --opt -u $user -p$password $db > /mnt/backup/ /mysql/$db.sqldone

After creation do chmod a+x mysqlbackup.sh so that the script can be executed

• To automate the job create a cronjob under /etc/cron.d called mysql_backup (or do it via crontab –e)

00 02 * * *     root    /usr/sbin/mysqlbackup.sh >/dev/null 2>&1

Just a few commandos to remind:

sh run

sh switch

sh conf

sh mac address-table inter gi 1/0/20

sh interfaces status

sh arp

wr

conf t

default interface gi/1/0/42

default switchport access vlan

conf t

interface gi/1/0/42

no shutdown

exit

sh interface status gi/1/0/42

conf t

interface gi/1/0/42

description *****SEPPL*****

exit

sh run int gi/1/0/42

conf t

interface GigabitEthernet1/0/28

description AT-KL-PROD-AP07

switchport trunk native vlan 200

switchport trunk allowed vlan 60,90,200

switchport mode trunk

switchport nonegotiate

switchport voice vlan 70

logging event trunk-status

spanning-tree portfast

Copy running-config startup-config

Examples:

interface GigabitEthernet1/0/1

description ***20 VLAN***

switchport access vlan 20

switchport mode access

switchport nonegotiate

switchport voice vlan 70

mls qos trust dscp

spanning-tree portfast

interface GigabitEthernet1/0/28

description TRUNKY TRUNKY

switchport trunk native vlan 200

switchport trunk allowed vlan 60,90,200

switchport mode trunk

switchport nonegotiate

switchport voice vlan 70

logging event trunk-status

spanning-tree portfast

interface GigabitEthernet2/0/23

description ESX-Server

switchport trunk encapsulation dot1q

switchport trunk native vlan 1999

switchport trunk allowed vlan 1,10,12,200

switchport mode trunk

switchport nonegotiate

logging event trunk-status

mls qos trust dscp

spanning-tree portfast trunk