Author: paul.deluca

How often should I update my Red Hat Enterprise Linux server?

We recommend that you install Red Hat Enterprise Linux updates on a regular basis, as they are intended to resolve bugs and fix security issues. How often you choose to install updates is up to you, but we would advise installing updates at least once a month.

As always, we recommend you perform a full system backup before installing any software or making hardware changes.

In most cases, installing Red Hat Enterprise Linux (RHEL) software updates will not impact Eclipse. The base software components that make up the core Eclipse package (UniVerse, JBoss, VSIFAX, etc.) are all installed and maintained separately from RHEL’s rpm software update mechanisms. These updates do have the ability to impact certain OS components used by Eclipse and various companion products (telnet-server, sendmail, postfix, vsftpd, samba, etc.), but the system is configured in such a way to minimize the impact of changes to these components.

Eclipse performs validation testing for each major release of the OS (RHEL 6, RHEL 7, etc.), and our server compatibility page will reflect the latest supported version(s) of the operating system. If we notice any issues resulting from a recent release of an OS package, our first response will be to resolve the problem directly with the vendor. If the software change necessitates changes to our software or configuration, we will provide workarounds as necessary for our existing customers and integrate the fix(es) into the current release of Eclipse.

What is the SOLAR.J2EE.CONNECTION phantom?

The SOLAR.J2EE.CONNECTION phantoms make up the pool of connections between the UniVerse database that powers Eclipse and the JBoss application server that powers Solar, Job Management and other newer applications.

The number of phantoms you see active on your system may increase or decrease depending on how your system utilization.

For more information on how to configure how many phantoms run, see Why are there so many J2EE phantoms running?

Install Linux via VNC

If your server doesn’t have a DRAC, iLO or other network KVM, you can access the RHEL installer over the network using VNC:

  • Boot from the RHEL DVD
  • At the prompt, type:
linux vnc
  • Skip the media check
  • Select language
  • Select automatic
  • Select network interface
  • Select DHCP or manual IP configuration
  • (Manual only) Enter IP address, subnet mask, gateway and DNS server
  • When prompted to connect, use a VNC viewer like TightVNC to access the server and continue in the graphical installer

Here’s a screencast showing the entire process from start to finish:
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How do I monitor system performance using nmon?

nmon is a free console-based performance monitoring tool from IBM. It works on both AIX and RHEL.

If nmon is not already installed, you must first install it:

To use nmon:

View a step-by-step screencast of this process:
Unable to display content. Adobe Flash is required.

  • Log into your server as root using a terminal emulator such as PuTTy (see also: How do I use PuTTy with my Eclipse server?)
  • (AIX only) Set the terminal emulation type to match the PuTTy console: 
    export TERM=xterm
  • Run: 
    nmon
  • Press the appropriate keys to launch or close various monitoring windows. Type “h” for help. Here are some common views:
    • “t”: display top processes
    • “t” then”u”: display top processes by CPU utilization and show command line arguments
    • “c”: display CPU utilization
    • “l”: display longer-term CPU utilization averages
    • “d”: display disk I/O graphs
    • “h”: display help

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