This document provides basic guidelines to show you how to configure the QNAP TS-x79 series Turbo NAS as the iSCSI datastore for VMware ESXi 5.0. The TS-x79 series Turbo NAS offers class-leading system architecture matched with 10 GbE networking performance designed to meet the needs of demanding server virtualization. With the built-in iSCSI feature, the Turbo NAS is an ideal storage solution for the VMware virtualization environment.
The following recommendations (illustrated in Figure 1) are provided for you to utilize the QNAP Turbo NAS as an iSCSI datastore in a virtualized environment.
1.Create each iSCSI target with only one LUN
Each iSCSI target on the QNAP Turbo NAS is created with two service threads to deal with protocol PDU sending and receiving. If the target hosts multiple LUNs, the IO requests for these LUNs will be served by the same thread set, which results in data transfer bottleneck. Therefore, you are recommended to assign only one LUN to an iSCSI target.
2.Use “instant allocation” to create iSCSI LUN
Choose “instant allocation” when creating an iSCSI LUN for higher read/write performance in an I/O intensive environment. Note that the creation time of the iSCSI LUN will be slower than that of a LUN created with “thin provisioning”.
3.Store the operation system (OS) and the data of a VM on different LUNs
Have a VM datastore to store a VM with a dedicated vmnic (virtual network interface card) and map another LUN to the VM to store its data. Use another vmnic to connect to the data.
4.Use multiple targets with LUNs to create an extended datastore to store the VMs
When a LUN is connected to the ESXi hosts, iSCSI will be represented as a single iSCSI queue on the NAS. When the LUN is shared among multiple virtual machine disks, all I/O has to serialize through the iSCSI queue and only one virtual disk’s traffic can traverse the queue at any point in time. This leaves all other virtual disks’ traffic waiting in line. The LUN and its respective iSCSI queue may become congested and the performance of the VMs may decrease. Therefore, you can create multiple targets with LUNs as an extended datastore to allow more iSCSI queues to deal with VMs access. In this practice, we will use four LUNs as an extended datastore in VMware.
5.For normal datastore, limit the number of VMs per datastore to 10
If you just want to have one LUN as a datastore, you are recommended to implement no more than 10 virtual machines per datastore. The actual number of VMs allowed may vary depending on the environment.
Be careful the datastore shared by multiple ESX hosts VMFS is a clustered file system and uses SCSI reservations as part of its distributed locking algorithms. Administrative operations, such as creating or deleting a virtual disk, extending a VMFS volume, or creating or deleting snapshots, result in metadata updates to the file system using locks, and thus result in SCSI reservations. A reservation causes the LUN to be available exclusively to a single ESX host for a brief period of time, thus impacts the VM performance.
The following items are required to deploy the Turbo NAS with VMware ESXi 5.0:
- One ESXi 5.0 host
- Three NIC ports on ESXi host
- Two Ethernet switches
- QNAP Turbo NAS TS-EC1279U-RP
Network configuration of ESXi host:
|vmnic||IP address/subnet mask||Remark|
|vmnic 0||10.8.12.28/23||Console management (not necessary)|
|vmnic 1||10.8.12.85/23||A dedicated interface for VM datastore|
|vmnic 2||184.108.40.206/16||A dedicated interface for VM data LUN|
Network configuration of TS-EC1279U-RP Turbo NAS :
|Network Interface||IP address/subnet mask||Remark|
|Ethernet 1||10.8.12.125/23||A dedicated interface for VM datastore|
|Ethernet 2||220.127.116.11/16||A dedicated interface for VM data LUN|
|Ethernet 3||Not used in this demonstration|
|Ethernet 4||Not used in this demonstration|
iSCSI configuration of TS-EC1279U-RP Turbo NAS:
|iSCSI Target||iSCSI LUN||Remark|
|DataTarget||DataLUN||To store VM data|
|VMTarget1||VMLUN1||For the extended VM datastore|
|VMTarget2||VMLUN2||For the extended VM datastore|
|VMTarget3||VMLUN3||For the extended VM datastore|
|VMTarget4||VMLUN4||For the extended VM datastore|
|A||0||To connect to Ethernet 1 of the Turbo NAS|
|A||1||To connect to vmnic 1 of the ESXi server|
|B||0||To connect to Ethernet 2 of the Turbo NAs|
|B||1||To connect vmnic 2 of the ESXi server|
Note: The iSCSI adapters should be on a private network.
Configure the network settings of the Turbo NAS
Login the web administration page of the Turbo NAS. Go to “System Administration” > “Network” > “TCP/IP”. Configure standalone network settings for Ethernet 1 and Ethernet 2.
- Ethernet 1 IP: 10.8.12.125
- Ethernet 2 IP: 18.104.22.168
Note: Enable “Balance-alb” bonding mode or 802.3ad aggregation mode (an 802.3ad compliant switch required) to allow inbound and outbound traffic link aggregation.
Create iSCSI targets with LUNs for the VM and its data on the NAS
Login the web administration page of the Turbo NAS. Go to “Disk Management” > “iSCSI” > “Target Management” and create five iSCSI targets, each with a instant allocation LUN (see Figure 6). VMLUNs (1-4) will be merged as an extended datastore to store your VM. DataLUN, 200 GB with instant allocation, will be used as the data storage for the VM.
For the details of creating iSCSI target and LUN on the Turbo NAS, please see the application note “Create and use the iSCSI target service on the QNAP NAS” on www.qnap.com/i/au/trade_teach/ Once the iSCSI targets and LUNs have been created on the Turbo NAS, use VMware vSphere Client to login the ESXi server.
Configure the network settings of the ESXi server
Run VMware vSphere Client and select the host. Under “Configuration” > “Hardware” > “Networking”, click “Add Networking” to add a vSwitch with a VMkernal Port (VMPath) for the VM datastore connection. The VM will use this iSCSI port to communicate with the NAS. The IP address of this iSCSI port is 10.8.12.85. Then, add another vSwitch with a VMkernal Port (DataPath) for the data connection of the VM. The IP address of this iSCSI port is 22.214.171.124.
Enable iSCSI software adapter in ESXi
Select the host. Under “Configuration” > “Hardware” > “Storage Adapters”, select “iSCSI Software Adapter”. Then click “Properties” in the “Details” panel.
Click “Configure” to enable the iSCSI software adapter.
Bind the iSCSI ports to the iSCSI adapter
Select the host. Under “Configuration” > “Hardware” > “Storage Adapters”, select “iSCSI Software Adapter”. Then click “Properties” in the “Details” panel. Go to the “Network Configuration” tab and then click “Add” to add the VMkernel ports: VMPath and VMdata.
Connect to the iSCSI targets
Select the host. Under “Configuration” > “Hardware” > “Storage Adapters”, select “iSCSI Software Adapter”. Then click “Properties” in the “Details” panel. Go to the “Dynamic Discovery” tab and then click “Add” to add one of your NAS IP address (10.8.12.125 or 126.96.36.199). Then click “Close” to rescan the software iSCSI bus adapter.
After rescanning the software iSCSI bus adapter, you can see the connected LUN in the “Details” panel.
Select the preferred path for each LUN
Right click each VMLUNs (1-4) and click “Manage Path…” to specify their paths.
Change Path Selection to “Fixed (VMware)”.
Then, select the dedicate path (10.8.12.125) and click “Preferred” to set the path for the VM connection.
Repeat the above steps to set up the preferred path (188.8.131.52) for DataLUN (200 GB).
Create and enable a datastore
Once the iSCSI targets have been connected, you can add your datastore on a LUN. Select the host. Under “Configuration” > “Hardware” > “Storage”, click “Add storage…” and select one of the VMLUNs (1 TB) to enable the new datastore (VMdatastore). After a few seconds, you will see the datastore in the ESXi server.
Merge other VMLUNs to the datastore
Select the host. Under “Configuration” > “Hardware” > “Storage”, right click VMdatastore and click “Properties”.
Select the other three VMLUNs and merge them as a datastore.
After all the VMLUNs are merged, the size of the VMdatastore will become 4 TB.
Create your VM and store it in the VM datastore
Right click the host to create a new virtual machine, select VMdatastore as its destination storage. Click “Next” and follow the wizard to create a VM.
Attach the DataLUN to the VM
Right click the VM that you just created, click “Edit Settings…” to add a new disk. Then, click “Next”.
Select “Raw Device Mappings” (RDM) and click “Next”.
Select DataLUN (200 GB) and click “Next”. Follow the wizard to add a new hard disk.
After a few seconds, a new hard disk will be added on your VM.
Your VM is ready to use
All the VM settings have been finished. Now start the VM and install your applications or save the access data in the RDM disk. If you wish to create another VM, please save the second VM to VMdatastore and create a new LUN on the Turbo NAS for its data access.