VCP4 Exam Blueprint – Objective 3.2 – Configure iSCSI SAN Storage

VCP4 Exam Blueprint

Objective 3.2 – Configure iSCSI SAN Storage

Knowledge

Page numbers refer to the VMware iSCSI SAN Configuration Guide pdf.

1.  Identify iSCSI SAN hardware components (pg. 9)
-Host Bus Adapters (HBA)
-Network Interface Cards (NIC)
-Switches
-Routers
-Cables
-Storage Processors (SP)
-Storage Disk Subsystems

2.  Determine use cases for hardware vs. software iSCSI initiators
-Hardware Initiator – specialized iSCSI HBA, responsible for all iSCSI and network processing and management
-Hardware initiators provide better performance and throughput by offloading iSCSI and TCP processing overhead.

-Software Initiator – Code built into the VMkernel that allows host to connect to the storage device through a std Ethernet adapter.
-Software initiators provide adequate performance for most applications, are less complex and easier to implement.

3.  Configure the iSCSI Software Initiator (pg. 30)
-Configure a VMkernel port for the physical network adapter.
-Enable the software iSCSI initiator
-Activate multi-pathing using the port binding technique on the ESX host if you use multiple network adapters
-Enable jumbo frames if needed and supported.  Jumbo frames must be enabled for each vSwitch via the CLI.
vicfg-vswitch -m <MTU> <vSwitch>
-For jumbo frames, you must create a VMkernel network interface enabled with jumbo frames.
esxcfg-vmknic -a -I <ip address> -n <netmask> -m <MTU> <port group name>

4.  Configure Dynamic/Static Discovery (pg. 35)
-Dynamic Discovery (Send Targets) – the server sends a list of available targets in response to the Send Targets request.
-Targets discovered via Dynamic Discovery are added to the Static Discovery tab
-Static Discovery – the initiator uses a list of targets (IP addresses and target names)
-Required privilege: Host.Configuration.Storage Partition Configuration
-Configuration>Storage Adapters>Properties>Dynamic Discovery>Add
-You cannot change the IP address, DNS name, or port number of an existing Send Targets server. delete the existing server and add a new one.

5.  Configure CHAP Authentication (pg. 37)
-ESX/ESXi supports CHAP at the adapter level.
-Software iSCSI supports per-target CHAP
-For software iSCSI, the CHAP name should not exceed 511 and the CHAP secret 255 alphanumeric characters.
-For hardware iSCSI, the CHAP name should not exceed 255 and the CHAP secret 100 alphanumeric characters.
-Required privilege: Host.Configuration.Storage Partition Configuration
-Configuration>Storage Adapters>Properties>General Tab>CHAP

6.  Configure VMkernel port binding for iSCSI Software multi-pathing  (pg. 32)
-You must create one VMkernel port for each network adapter before you can set up multipathing
-esxcli swiscsi nic add -n <port_name> -d <vmhba>

7.  Discover LUNs  (pg. 60)
-Perform a rescan each time you create a new LUN on the SAN
-By default, the VMkernel scans for LUN 0 to LUN 255 for every target (a total of 256 LUNs).
-You cannot discover LUNs with a LUN ID number that is greater than 255.
-Modify the Disk.MaxLUN parameter to improve LUN discovery speed.
-Configuration>Advanced Settings>Disk>Disk.MaxLUN

8.  Identify iSCSI addressing in the context of the host (pg. 10)
-IP Address
-iSCSI name (world wide unique name)
-iSCSI alias (friendly name, not unique)

-IQN (iSCSI Qualified Name) format  iqn.yyy-mm.naming-authority:unique name
-the naming authority is listed in reverse syntax

-EUI (Enterprise Unique Identifiers) format  eui.<16 hex digits>

Tools
-iSCSI SAN Configuration Guide
-Product Documentation
-VMware vSphere Client
-esxcli

Blade server local storage debate (SSD or SAS)

I found myself pulled into a design debate at the office this afternoon.

It centered on whether or not we should be using SSD’s as the boot drives for new blade installations.

SSD’s seem like a good idea at first glance;

Fewer moving parts = increased reliability
Greener solution – requires less power
Generates less heat
Quieter

But when you see what Dell is charging for SSD’s for the m710 blade you’ll likely have second thoughts.

Considering these prices, I’d be better off going with a hardware initiator and booting directly from the SAN.

Looks like we’re staying with a RAID1 SAS configuration for now.

Dell Equallogic PS5500e iSCSI SAN

The PS5500e provides 24TB of RAID 50 storage.

In this implementation, the PS5500 is providing storage for a cluster of nine Vmware ESX servers.

The ESX server cluster consists of nine Dell blades with dual quad-core CPU’s and 32Gig of RAM.

PS-5500e chassis - ready for drives

PS-5500e loaded with 48 1TB drives

-

After the chassis is installed in the rack, the drives load from the top of the unit.

It takes a few minutes to unpack 48 drives and install them in the chassis.

It’s pretty impressive looking once all of the drives installed.

-

-

-