Author: Dawit Gebru

How do I perform a manual rsync backup on Linux?

If your system is configured to perform an rsync backup as part of the standard snapshot script, simply run the following command:

at now -f /u2/UTILS/bin/snapsave_linux.sh

To schedule the backup at specific date and time, for example at 11PM today, change now to 23:00.

at 23:00 -f /u2/UTILS/bin/snapsave_linux.sh

This script will suspend your database, take snapshots of the database files and create a full tape backup. You will not see any output in your console session, because the script creates a separate log file under /tmp/snapsave.log.

If you have already created the snapshot filesystem, but you want to perform a separate manual tape backup:

 rsync  -avz --delete --stats /snap/u2/   /mnt/nas/rsync/

If there are no snapshots present, but no users are on the system and you want to perform a manual rsync backup:

 rsync  -avz --delete --stats /u2/   /mnt/nas/rsync/

References:
How to use the at command
How to use rsync

RHEL 6 Installation Guide for Eclipse

  • Configure RAID arrays
  • Boot from RHEL6 image
  • Press ENTER to start the installer
  • Select Basic Storage Devices -> Next -> Re-Initialize All
  • Enter the hostname, for example: eclipse-customername
  • Select ‘Configure Network -> eth0 -> Edit -> IPv4 Settings tab -> Method: Manual -> Add
  • Enter IP address, netmask, gateway, DNS server -> Apply -> Close
  • Select the closest city to the server’s final physical location
  • Enter root password -> Use Anyway
  • Select Create Custom Layout
  • Select the OS (rootvg) disk array -> double-click or use the arrow to move it under Install Target Devices -> Next
  • Select the OS array (/dev/sda) -> Create -> Standard Partition -> Create -> Mount point: /boot -> Allowable drives: /dev/sda -> Size: 200MB -> OK
  • Select the OS array (/dev/sda) -> Create -> LVM Physical Volume -> Create -> Type: physical volume (LVM) -> Allowable drives: /dev/sda -> Size: Fill to
  • maximum -> OK
  • Select the OS LVM PV (/dev/sda2) -> Create -> LVM Volume Group -> Create -Volume Group Name: rootvg
  • Add -> Mount point: / -> Name: root -> Size: 30720 (30GB) -> OK
  • Add -> Mount point: /esupport -> Name: esupport -> Size: 4096 (4GB) -> OK
  • Add -> File System Type: swap -> Name: swap -> Size: 4096 (4GB) -> OK
    • swap sized based on the amount of system RAM:
    • 4-16 GB RAM = 4096 MB
    • 16-64 GB RAM = 8192 MB
    • 64-256 GB RAM = 16384 MB
  • Continue, accepting defaults until you reach the software selection screen
  • Select Software Development Workstation -> Next
  • After the installation process has completed, reboot

How do I check for duplicate IP addresses in Linux?

Linux doesn’t do an active monitoring or reporting of duplicate ip, after the interface is initialized. To check for duplicate IP addresses in Linux:

Log into your server via console and from the command line run

arping -D -q -I eth0 -c 2 192.168.1.250 ; echo $?

If the above commands return 0, then no one responded to your arp request and therefore no one else is using your IP address.

References:
https://access.redhat.com/solutions/35057
http://www.cyberciti.biz/faq/linux-duplicate-address-detection-with-arping/

How do I change a printer’s IP address in AIX?

The mappings of IP addresses to “lp” names are contained in the /etc/hosts configuration file. To change the IP address:

    Log into your server as root user via Eterm or PuTTY
    Edit the /etc/hosts file using vi: 
vi /etc/hosts
    Locate the entry for the printer(s) you wish to change
    Make the change
    Save the file and quit