The Basics of an iSCSI San setup

 

For this entry, I will set out to describe the basics of an iSCSI SAN (Storage Area Network).  This is basically a set of disks connected together in a device and often raided together to create 1 lump of storage.  This storage device is connected to PC devices (usually Servers) over the network using very fast, large bandwidth, connections (shown below in orange).

iSCSI IP SAN Setup

iSCSI SAN Connected in a basic Network setup.

iSCSI SAN in the Virtualised World

These days, environments are being virtualised using platforms such as VMWare or Citrix XenDesktop or Microsoft’s Virtual PC.  Below is a very simple view of 2 Virtual PCs with access to Volumes stored on the iSCSI SAN.  Using a host platform such as VMWare ESX, the actual Operating System and entire “C:\” drive can run on this volume.  The Virtual Machine runs on the SAN (in terms of storage).

iSCSI IP SAN Setup with VM Hosts

Simplified view of 2 VMWare Hosts running on a single physical server.

Here the devices, both physical and virtual hosts have separate network connections for Network communication and iSCSI Data traffic.  This is to give the PC/Server the best performance when shuffling lots of data around between the host and iSCSI SAN.  Separate Network switching is often used to prevent bottlenecks and slow network performance.

Stonefly SCVM iSCSI Demo

It’s not essential to have separate network connections and for simplicity in the following parts of this blog, I have setup a simple demonstration using just a single IP Address and connection per host (these share the same network as the conventional network connections).

Below shows how I have installed 3 VMWare Hosts onto my Windows 7 Ultimate 64 bit Desktop PC.

iSCSI IP SAN Setup Demo

Simple setup for this iSCSI SAN demo

The first is a Redhat Enterprise Linux 5 64-bit Virtual Machine with Stonefly’s SCVM available as a free trial from http://www.stonefly.com/products/software/scvm/ more on this later. The other 2 VM’s are Windows 2003 server.

All versions of Windows from XP upwards are capable of connecting to an iSCSI SAN using the iSCSI Initator Software available to download from http://www.microsoft.com/en-gb/download/details.aspx?id=18986 though it comes built in, with all Windows Systems since Vista. This software creates the connection to the SAN.

Stonefly’s SCVM software is provided via an ISO file which I used to install the Red Hat OS into my VM.  Of course, the idea is that you use a server with a lot of storage to install this Operating System and software.  For enterprise solutions, the server would ideally have a 10Gb Ethernet card and be connected to a 10Gb Network Switch (shown in orange in my graphics).  The server would also have a 10/100Mb network card, which it would use to connect to the management of the software through SSH or the web browser (shown in green in my graphics).

For the demo my Windows 7 PC has an extra 1TB Spinning Disk mounted to drive E:\ (I also have a Future Storage 240GB SSD as my C:\ Drive).

I installed all VM’s into E:\VMs folder – I also created a 20GB Virtual disk in the settings for the SCVM Virtual Machine which I will use to store the Volumes, and 2 Bridged Network Cards.

VMWare Player SCVM

Stonefly SCVM and two Windows 2003 servers created in VMWare Player

SCVM VMWare Settings

Stonefly SCVM VM Settings

I’m just using VMWare’s Player – downloadable from http://www.vmware.com/products/player/

This is simplicity itself.  If you’ve not used this before you just load the iso file (CD Image) into the virtual CD/DVD and when you turn the VM on it boots from the iso as if it was a CD/DVD.

Start SCVM Virtual Machine

VMware Player

Once the VM has started the OS should install within just a few minutes – it will reboot and be left with the screen similar to below – the IP address defaults to 192.168.0.254 but you need to change it to suit your own network.

SCVM Loaded

Stonefly SCVM Loaded

Here you can login using the default username: console and password: cons100o – once logged it to the console you can adjust the Network settings to suit your installation.  Once this is complete, using the simple DOS style menu (select option 2 – Network – enter the corresponding numbers for each value to change – 6 to save – q to quit).

Once back at the above screen you can then configure everything from the web browser. In my example by going to https://192.168.7.59/.

This should show the following screen:

Stonefly SCVM Web Interface

Stonefly SCVM Front screen viewed in Google Chrome Browser

Login using the default username: stonefly and password: stonefly (these can be changed within the system once logged in).

The next step is to use the iSCSI initiator on the host to connect to the iSCSI Server.

This can be found the the control panel (if not it can be downloaded from http://www.microsoft.com/en-gb/download/details.aspx?id=18986).

iSCI Initiator

Clicking the Discovery Tab allows you add the IP Address of the iSCSI SAN as a Target Portal.

iSCSI Initiator - Add Portal

iSCI Initiator - Add Target Portal

Default port is 3260.  Once connected – the hosts will then appear within the Stonefly SCVM web interface.

Stonefly SCVM Volumes

The next task is to carve up the available storage into Volumes (the available storage is the 20GB Hard Disk 2 created before the VM was built).  These volumes can be assigned to the hosts on the network.  It really is simple to do by clicking on Volumes –> Create New Volume:

Stonefly SCVM Add Volumes

SCVM Create Volume

Here, you name the volume, enter Notes and allocate an amount, or all of the Available Space to the Volume. Once created – you have the opportunity to allocate the Volume to a Host.

Stonefly SCVM Select Host

SCVM Allocate Volume to Host

Once added the Volume can have a partition added to it and assigned a disk drive.  To do this right click My Computer or (Computer Manage in Windows 7).  Select Disk Management.

iSCSI Volume - Disk Management

My Computer –> Manage –> Disk Management

Create a Basic Disk – and Initialize.

iSCSI Volume - Disk Management - Initialize Disk

iSCSI Volume - Disk Management - Initialize Disk 2

iSCSI Volume - Disk Management - Convert Disk

iSCSI Volume - Disk Management - Primary Partition

Assign a drive letter of your choice (I chose letter I:\). The disk then appears as a Hard disk in your My Computer listing

iSCSI Volume - Partition Created - Disk Loaded

SCVM Volumes Completed

Once the Volumes have been setup on the SCVM System and on the hosts you can see the details of this within the SCVM interface.

Stonefly iSCSI SCVM Volume Summary

Viewing the details shows

Stonefly iSCSI SCVM Volume Details

You can also see the iSCSI Server’s Resources via the Resources Menu.

Stonefly iSCSI SCVM Resources

iSCSI IP SAN from Stonefly SCVM

So there we have it – We have turned our Windows 7 Desktop PC into an iSCSI IP SAN using a VM created in VMWare Player (running Redhat 5).  We then served 2 volumes to 2 Virtual Machines running Windows 2003 Server.  We have not included any security setup using CHAP, nor covered replication using Synchronous or ASynchronous technologies (these are for further posts).

Buy Stonefly SCVM from Future Storage

If you are interested in this technology and would like to try before you buy – there is a 45 day free trial available at http://www.stonefly.com/products/software/scvm/ and licences can be purchased through Future Storage – Please get in touch via 0845 299 0793 or email at http://www.futurestorage.co.uk/web-enquiry-16-w.asp

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