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Import OVF VM Into VMware Workstation 8

VMware Workstation can import virtual machines packaged in the OVF format, the process takes little time and is surprising easy to follow.

From VMware Workstation go to File > Open…

OVF import VMware 1

You are now presented with a window, on the lower right corner select Open Virtual Machine Format Images (*.ovf, *.ova) from the drop down menu.

OVF import VMware 2

Browse to the location where the virtual machine resides and select it, click on Open.

OVF import VMware 3

Now you can either choose to rename the virtual machine and modify path, the defaults work for me. Click on Import to start the process.

OVF import VMware 4

Look at that progress bar, be patient.

OVF import VMware 5

The newly imported virtual machine should now be usable in VMware Workstation.

OVF import VMware 6

If you have any questions leave a comment below.

Cisco Continuous Ping

If you ping an address from a Cisco router the ping will be repeated five times, to increase the amount of repeated pings all you need to do is make use of the repeat parameter. The command below will ping 10.10.10.1 1000 times.

R1# ping 10.10.10.1 repeat 1000

Breakdown

ping: Execute ping
10.10.10.1: Address of the host we weill be pinging
repeat: Ping should be repeated
1000: Repeat ping 1000 times

Repeat In Action

R2# ping 10.10.10.1 repeat 1000

Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 10.10.10.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/5/8 ms

Scan a subnet with Nmap

Simple Nmap combination useful if you need to scan an entire subnet for active hosts and the IP addresses used by the same. I am not an expert on Nmap if you have a better method let me know.

1. From a command line window issue the command below.

nmap -v -sn 192.168.1.0/24
  • -v
  • Vervose

  • -sn
  • Ping scan – disable port scan

2. Nmap outputs its findings along with the IP address and MAC address of the clients on the subnet.

# nmap -v -sn 192.168.1.0/24

Starting Nmap 5.51 ( http://nmap.org ) at 2012-11-05 00:10 Mountain Standard Time
Initiating ARP Ping Scan at 00:10
Scanning 11 hosts [1 port/host]
Completed ARP Ping Scan at 00:10, 0.53s elapsed (11 total hosts)
Initiating Parallel DNS resolution of 11 hosts. at 00:10
Completed Parallel DNS resolution of 11 hosts. at 00:10, 16.50s elapsed
Nmap scan report for 192.168.1.0 [host down]
Nmap scan report for 192.168.1.1
Host is up (0.0010s latency).
MAC Address: 00:90:7F:26:3E:13 (WatchGuard Technologies)
Nmap scan report for 192.168.1.2 [host down]
Nmap scan report for 192.168.1.10 [host down]
Initiating Parallel DNS resolution of 1 host. at 00:10
Completed Parallel DNS resolution of 1 host. at 00:11, 16.50s elapsed
Nmap scan report for 192.168.1.11
Host is up.
Initiating ARP Ping Scan at 00:11
Scanning 244 hosts [1 port/host]
Completed ARP Ping Scan at 00:11, 1.96s elapsed (244 total hosts)
Initiating Parallel DNS resolution of 244 hosts. at 00:11
Completed Parallel DNS resolution of 244 hosts. at 00:11, 16.50s elapsed
Nmap scan report for 192.168.1.12 [host down]
Nmap scan report for 192.168.1.17 [host down]
Nmap scan report for 192.168.1.18
Host is up (0.0019s latency).
MAC Address: 00:0C:29:97:30:0A (VMware)
Nmap scan report for 192.168.1.19 [host down]
Nmap scan report for 192.168.1.255 [host down]
Read data files from: C:Program Files (x86)Nmap
Nmap done: 256 IP addresses (3 hosts up) scanned in 52.16 seconds
           Raw packets sent: 509 (14.252KB) | Rcvd: 3 (84B)

Windows: Missing Performance Counter Value

Not the end of the world but I did come across an annoying problem on one of my workstations, for some unexplained reason the Windows Resource Manager would not display any the drives connected to the system.

Disk resource

1. To solve this problem we’ll need a command line window. Go to Start > All Programs > Accessories > Command Prompt

2. Restore counter setting by issuing the for following command in the Windows command line.

lodctr /r

3. Just to be sure restart the system. Now the values should be back to normal.

Resources:

http://technet.microsoft.com/en-us/library/bb490926.aspx

Cisco: %Error opening tftp://255.255.255.255

Router#
%Error opening tftp://255.255.255.255/network-confg (Timed out)
%Error opening tftp://255.255.255.255/cisconet.cfg (Timed out)

The error above is the result of the Cisco IOS attempting to retrieve config files from a TFTP server. Let’s turn this annoying feature off…

Change over to Global Config.

R1# config t

Turn off the service.

R1(config)# no service config
R1(config)# exit

Reload the device and admire your productivity. You should no longer be bothered by the previous error.

R1# reload

Questions and comments are always welcome, feel free to use the form below.

Change the Keyboard Layout for CentOS / Scientific Linux

Yes, for some reason one of my VMs was configured with a different keyboard layout:

[root@system7]# cat /etc/sysconfig/keyboard

KEYTABLE="it"
MODEL="pc105"
LAYOUT="it"
KEYBOARDTYPE="pc"

The solution is quite simple all you have to do is edit /etc/sysconfig/keyboard with your favorite editor to make the keyboard layout US friendly. I am using VI as an example you can use whatever text editor you prefer.

[root@system7]# vi /etc/sysconfig/keyboard

KEYTABLE="us"
MODEL="pc105+inet"
LAYOUT="us"
KEYBOARDTYPE="pc"

Save and Exit the text editor. Restart the system so the changes can take effect, now you should have a keyboard layout that you are familiar with.

VMware: Taking Ownership of this Virtual Machine Failed

Could not open virtual machine: [vm name]

Taking ownership of the virtual machine is failed

This is an error that occurs mostly as the result of an unclean shutdown either because the host or guest didn’t have the time to properly stop operations. Fortunately this error can be solved with a few easy to follow steps.

VM Path

This is the type of error you will be presented with every time you try to start the virtual machine. Take note of the virtual machine path, you will need to navigate to where the virtual machine is located. Click on OK to dismiss.

VM Locked

In my case all virtual machines are stored in E:Virtualization(yours will be different). The VM I am looking for is Ubuntu 12.04 Server 64-bit.

VM Locked

Solution

With the VM directory open now search for all files with the extension .lck this are the files are responsible for the error. You have two options in order to solve the problem:

  1. You can move all files with the extension .lck to another directory that isn’t the same as the current one.
  2. Or you can do what I do and erase all .lck files. Only erase those ending with .lck.

VM Locked

Results

Now go back and try to start the virtual machine. This time the VM should start like usual.

VMware Locked

Linux: How to Find a Hard Drive Serial Number

Like many other times I had to retrieve the serial number of a faulty SATA drive on a Linux box. You should retrieve and compare the serial number before replacing to reduce the chance of replacing a working drive instead of a faulty drive. Hdparm is a utility that allows for the retrieval of the serial number, if I remember correctly hdparm is included by default on Ubuntu, Scientific Linux users can install hdparm from the repositories by using yum install hdparm.

Note: hdparm requires access to the root account or similar.

Retrieve The Info

The hdparm output will be rather long, but all you need to look for is Serial Number: xx-xxxxxxxxx, this is where the serial number for the drive is contained.

# hdparm -I /dev/sdf

/dev/sda:

ATA device, with non-removable media
	Model Number:       WDC WD5001AALS-00L3B2
	Serial Number:      WD-WMASZ0044725
	Firmware Revision:  01.03B01
	Transport:          Serial, SATA 1.0a, SATA II Extensions, SATA Rev 2.5
Standards:
	Supported: 8 7 6 5
	Likely used: 8

Now you can physically verify whether the drive label matches the serial number you just obtained with the help of hdparm. Check twice you wouldn’t want to pull a working drive instead.

Wipe Multiple Drives Simultaneously

This is one way you can wipe or overwrite multiple drives simultaneously it requires a little tool called Dcfldd which is available for all distributions.

If you are an Ubuntu user you can install Dcfldd from the repositories:

# apt-get install dcfldd

CentOS and Scientific Linux can install Dcfldd from the RepoForge repositories:

# yum install dcfldd

Dcfldd Wipe

Dcfldd will overwrite drive sdb and sdc with zeroes. You can also increase the block size if you want.

# dcfldd if=/dev/zero of=/dev/sdb of=/dev/sdc bs=4M

If the operation completes successfully you should receive the message No space left on device meaning there is nothing left to overwrite on the drive(s).

5120 blocks (20480Mb) written.dcfldd:: No space left on device

If you don’t beliieve me here is a screenshot displaying the activity taking place on both sdb and sdc.

nmon

Conlusion

Dcfldd can become useful for when you have get rid of several drives at once, as you saw the command is quite easy to remember. If you have any questions feel free to leave a comment below and I will do my best to reply as soon as possible.

Home page: Dcfldd