The Top Five Virtualization Mistakes

MISTAKE #1: LEAVING THE NETWORK UNSEGMENTED
MISTAKE #2: VIRTUALIZING ONLY THE SERVERS
MISTAKE #3: FORGETTING TO VIRTUALIZE THE BRANCH OFFICE
MISTAKE #4: FORGETTING TO VIRTUALIZE THE NETWORK AS PART OF THE DISASTER RECOVERY PLAN
MISTAKE #5: FORGETTING TO SELL YOUR OLD HARDWARE ON EBAY

The conclusion:

To get the most out of your virtualization project and to avoid common mistakes, here’s a checklist to use in planning.
1. Look for unsegmented networks that might be at risk from virtualization and use virtualization tools to segment them.
2. Look at the networking functions associated with servers you plan to virtualize and virtualize them together.
3. Consider networking functions such as routing, firewalls, and VPN as part of branch virtualization projects. Putting them on the same hardware as other applications will get you a long way toward “branch in a box.”
4. Use virtualize to include network functions in disaster recovery plans, so that when there’s a disaster, your routing, firewall, and VPN will come back online along with the rest of your compute resources.
5. Sell off specialized network hardware on eBay. By using x86 hardware and virtualization, you’ll save money on purchase, operation, and maintenance.

The first public comparison between the two blade systems comes from Steve Kaplan, Vice President Data Center Virtualization Practice at INX.

His technical analysis is well worth a read.  

原文 http://www.novell.com/connectionmagazine/2007/q3/tech_talk_9.html?sourceid=NCM_q3_07_tt9

WireShark 截图

Switches only forward four types of traffic:

• Broadcasts
• Multicasts
• Traffic to and from the connected system’s MAC address
• Traffic to an unknown MAC address

作者的监听解决方案：
half-duplex lines：a simple four-port hub
full-duplex lines：a small network tap

Tapping into Full Duplex Networks

Sometimes referred to as “walkie-talkie” style communications, the simple half-duplex environment supports traffic moving in one direction at a time, transmit or receive, but never both simultaneously. Alternatively, fullduplex networks support two communications channels for simultaneous transmit and receive. A simple hub doesn’t support full-duplex communications, but a full-duplex tap does.

Full duplex taps are placed inline—typically acting as passive devices. Taps are simple to set up. Let’s say, for example, that you want to tap into a full-duplex link that uses CAT5e cable between two network routers. One CAT5e cable runs from the first router to port A. A second CAT5e cable runs from port B to the second router. Monitor ports connect to the analyzer allowing you to see a copy of all traffic.

There are two flavors of full-duplex taps—aggregating and non-aggregating taps. Aggregating taps combine the data from the transmit and receive channels into a single monitor port allowing you to connect a single analyzer to listen to both traffic channels. Non-aggregating taps as shown in Figure, do not combine the transmit and receive streams. You must connect the monitor ports to two separate analyzers or an analyzer with two NICs installed.

Attention!!!

If you use non-aggregating taps and two separate analyzers, you should time sync the two analyzers using NTP (Network Time Protocol) to ensure data in your streams can be merged into proper order.

For the network blade of a blade server to support an ESX Server port group with VLAN tagged traffic, you must configure the blade to support 802.1Q and configure the port as a tagged port.

The method for configuring a port as a tagged port differs from server to server. The following list describes how to configure a tagged port on three of the most commonly used blade servers:

• HP Blade — Set the port’s VLAN Tagging to enabled.
• Dell PowerEdge — Set the port to Tagged.
• IBM eServer Blade Center — Select Tag in the port’s configuration.

To configure a virtual machine port group with VLAN on a blade server

1. Log into the VMware VI Client and select the server from the inventory panel.

   The hardware configuration page for this server appears.

2. Click the Configuration tab, and click Networking.
3. On the right side of the screen, click Properties for vSwitch associated with the service console.
4. On the Ports tab, click Add.

   The Add Network Wizard appears.

5. As a connection type, select Virtual Machines, which is the default.
6. Click Next.

   The Connection Settings page appears.
   

7. Under Port Group Properties, enter a network label that identifies the port group that you are creating.
   Use network labels to identify migration-compatible connections common to two or more hosts.
8. In the VLAN ID field, enter a number between 1 and 4094.
   If you are unsure what to enter, leave this blank or ask your network administrator.
9. Click Next.
   The Ready to Complete page appears.
   

10. After you have determined that the vSwitch is configured correctly, click Finish.

To configure a VMkernel port with VLAN on a blade server

1. Log into the VMware VI Client and select the server from the inventory panel.

   The hardware configuration page for this server appears.

2. Click the Configuration tab, and click Networking.
3. On the right side of the screen, click Properties for vSwitch associated with the service console.
4. On the Ports tab, click Add.

   The Add Network Wizard appears.

5. Select VMkernel and click Next.

   This lets you connect the VMkernel, which runs services for VMotion and IP storage (NFS or iSCSI), to the physical network.
   The Connection Settings page appears.

6. Under Port Group Properties, select or enter a network label and a VLAN ID.
   • Network Label — A name that identifies the port group that you are creating. This is the label that you specify when configuring a virtual adapter to be attached to this port group, when configuring VMkernel services, such as VMotion and IP storage.
   • VLAN ID — Identifies the VLAN that the port group’s network traffic will use.
7. Select the Use this port group for VMotion check box to enable this port group to advertise itself to another ESX Server as the network connection where VMotion traffic should be sent.

   You can enable this property for only one VMotion and IP storage port group for each ESX Server host. If this property is not enabled for any port group, migration with VMotion to this host is not possible.

   

8. Under IP Settings, click Edit to set the VMkernel Default Gateway for VMkernel services, such as VMotion, NAS, and iSCSI

   Note

   Make sure that you set a default gateway for the port that you created. VirtualCenter 2 behaves differently here from VirtualCenter 1.x. You must use a valid IP address to configure the VMkernel IP stack, not a dummy address.

   The DNS and Routing Configuration dialog box appears. Under the DNS Configuration tab, the name of the host is entered into the name field by default. The DNS server addresses that were specified during installation are also preselected as is the domain.
   Under the Routing tab, the service console and the VMkernel each need their own gateway information. A gateway is needed if connectivity to machines not on the same IP subnet as the service console or VMkernel.
   Static IP settings is the default.

9. Click OK to save your changes, and close the DNS Configuration and Routing dialog box.
10. Click Next.
11. Use the Back button to make any changes.
12. Review your changes on the Ready to Complete page and click Finish.

Before you can configure iSCSI storage, you must create a VMkernel port to handle iSCSI networking and a service console connection to the iSCSI network.

To create a VMkernel port for software iSCSI

1. Log into the VMware VI Client, and select the server from the inventory panel.
   The hardware configuration page for this server appears.
2. Click the Configuration tab, and click Networking.
3. Click the Add Networking link.
4. Select VMkernel and click Next.
   This lets you connect the VMkernel, which runs services for iSCSI storage, to the physical network.
   The Network Access page appears.

5. Select the vSwitch you want to use or the Create a virtual switch radio button.
6. Select the check boxes for the network adapters your vSwitch will use.
   
   Your choices appear in the Preview pane.
   Select adapters for each vSwitch so that virtual machines or other services that connect through the adapter can reach the correct Ethernet segment. If no adapters appear under Create a new virtual switch, this means that all the network adapters in the system are being used by existing vSwitches.

7. Click Next.
   The Connection Settings page appears.
8. Under Port Group Properties, select or enter a network label and a VLAN ID.
   • Network Label — A name that identifies the port group that you are creating. This is the label that you specify when configuring a virtual adapter to be attached to this port group, when configuring iSCSI storage.
   • VLAN ID — Identifies the VLAN that the port group’s network traffic will use.
     

   • Under IP Settings, click Edit to set the VMkernel Default Gateway for iSCSI.

     The DNS and Routing Configuration dialog box appears. Under the DNS Configuration tab, the name of the host is entered into the name field by default. The DNS server addresses that were specified during installation are also preselected as is the domain.
     
     Under the Routing tab, the service console and the VMkernel each need their own gateway information. A gateway is needed for connectivity to machines not on the same IP subnet as the service console or VMkernel.
     

     Note

     Make sure that you set a default gateway for the port that you created. You must use a valid static IP address to configure the VMkernel stack.

9. Click OK to save your changes, and close the DNS and Routing Configuration dialog box.
10. Click Next.
11. Use the Back button to make any changes.
12. Review your changes on the Ready to Complete page and click Finish.

After you create a VMkernel port for iSCSI, you must create a service console connection on the same vSwitch as the VMkernel port.

To configure a service console connection for software iSCSI storage

1. Log into the VMware VI Client and select the server from the inventory panel.
   The hardware configuration page for this server appears.
2. Click the Configuration tab, and click Networking.
3. On the right side of the screen, click Properties for vSwitch associated with the VMkernel port you just created.
4. On the Ports tab, click Add.
   The Add Network Wizard appears.
   

5. As a connection type, select Service Console and click Next.
   The Connection Settings screen appears.

6. Under Port Group Properties, enter a network label that identifies the port group that you are creating.
   
   Newer ports and port groups appear at the top of the vSwitch diagram.

7. Enter the IP Address and Subnet Mask, or select the DHCP option Obtain IP setting automatically for the IP address and subnet mask.
8. Click the Edit button to set the Service Console Default Gateway.
9. Click Next.

   The Ready to Complete screen appears.
   

10. After you have determined that the vSwitch is configured correctly, click Finish.

After you create a VMkernel port and service console connection, you are able to enable and configure software iSCSI storage.