Author: paul.deluca

How do I unmount my Dell RD1000?

To unmount your Dell RD1000 USB drive:

umount /mnt/rd1000

If the unmount command is successful, the command will return you to the prompt without error.

To verify that the drive is unmounted:

mount | grep rd1000

If the drive is not mounted, the mount command will return no information.

To mount your Dell RD1000 USB drive:

mount /mnt/rd1000

Remove a Printer from Linux

Remove the printer’s entry from the UV spooler configuration file using a text editor (e.g. vim)

vim /usr/spool/uv/sp.config

Refresh the UniVerse spooler to re-read the configuration file:

usa -R

Remove the UniVerse driver file (e.g. lp15, replace lp15 with the appropriate print queue number):

rm /var/spool/uv/lp15.dvr
or
rm /usr/spool/uv/lp15.dvr

Remove the printer’s entry in the /etc/hosts file using a text editor (e.g. vim):

vim /etc/hosts

Remove the CUPS queue (e.g. lp15, replace lp15 with the appropriate print queue number):

lpadmin -x lp15

How do I monitor process I/O using iotop?

iotop is a utility for Linux that operates in a similar manner to the top utility, but it displays the I/O activity of each process.

Installation

First, you must enable the EPEL software repository:

For servers running RHEL 5:

rpm -Uvh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm

For servers running RHEL 6:

rpm -Uvh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-7.noarch.rpm

To install iotop:

yum -y install iotop

Usage

To display only the processes currently performing I/O:

iotop -o

To display the manual:

man iotop

Resources

Installing Memory in an IBM p520 or p52a Server

Reminder: always follow our best practices when performing any system maintenance.

For detailed instructions and videos covering the entire memory installation procedure, please see IBM’s website: Install model 285 or 52x memory modules

Installation rules:

  • If your server does not have ports P1-T3 and P1-T4 on the back, install the memory in the following order:
    • The first memory module pair is placed into memory module slots C9 and C16.
    • The second memory module pair is placed into memory module slots C11 and C14.
    • The third memory module pair is placed into memory module slots C10 and C15.
    • The fourth memory module pair is placed into memory module slots C12 and C13.
  • If your server has ports P1-T3 and P1-T4 on the back, install the memory in the following order:
    • The first quad of memory modules is placed into memory module slots C9, C11, C14, and C16.
    • The second quad of memory modules is plugged into memory module slots C10, C12, C13, and C15.

If you encounter any issues while performing the upgrade, please contact IBM hardware support.

Configure DNS on AIX

Configure DNS

To configure DNS on an AIX server:

Add the DNS server(s) to the /etc/resolv.conf configuration file:

vi /etc/resolv.conf

Add or update line(s) for each DNS server, one per line, as shown in the example below:

nameserver 192.168.1.100
nameserver 192.168.1.101

Enable DNS in the /etc/netsvc.conf configuration file:

vi /etc/netsvc.conf

At the bottom of the file, comment out the existing hosts entry, and add one that enables name lookups via DNS (aka bind), as shown in the example below:

#hosts=local
hosts=local,bind

Disabling DNS

If DNS is enabled but not working properly, you may see issues such as delayed OS logins or JBoss not starting correctly. To troubleshoot these and similar issues, we recommend that you temporarily disable DNS and try recreating the problem.

First, comment out any entries in the /etc/resolv.conf file:

vi /etc/resolv.conf

#nameserver 192.168.1.1

Then, change the hosts line in the /etc/netsvc.conf back to use only the local /etc/hosts file for lookups, as shown in the example below:

vi /etc/netsvc.conf

hosts=local
#hosts=local,bind

Troubleshooting DNS

To test whether or not DNS is working, you can try pinging an Internet address or looking up names, as shown in the examples below:

ping epicor.com
nslookup epicor.com

You should also verify that your Eclipse server is configured with a fully-qualified domain name (FQDN) that can be looked up via both its name and IP address. For example, a server with the hostname eclipse.customername.com and an IP address of 192.168.1.100 should show now errors when running nslookups on both entries:

nslookup eclipse
nslookup eclipse.customername.com
nslookup 192.168.1.100