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Fun with FreeNAS – iSCSI – When a local disk is not local

with 9 comments

Read our related posting first –

NAS for Clunkers: How to turn that old PC into a high tech Network Storage, Web Server, and Torrent Server

“iSCSI uses TCP/IP (typically TCP ports 860 and 3260). In essence, iSCSI simply allows two hosts to negotiate and then exchange SCSI commands using IP networks.

By doing this iSCSI takes a popular high-performance local storage bus and emulates it over wide-area networks, creating a storage area network (SAN). Unlike some SAN protocols, iSCSI requires no dedicated cabling; it can be run over existing switching and IP infrastructure.

As a result, iSCSI is often seen as a low-cost alternative to Fibre Channel, which requires dedicated infrastructure.”

FreeNAS_Logo

The Further Adventures….

Further adventures with FreeNAS running on a PC Clunker tucked away in the basement…

I decided to try to get iSCSI to work in FreeNAS.  Both Windows Vista and Windows 7 has built-in support for iSCSI.

What is iSCSI?

What is iSCSI?  In a few words, iSCSI is the SCSI protocol over an IP network.

And what is SCSI?  SCSI is a protocol that a computer can use to talk to peripherals of all kinds.

The Apple Mac used SCSI a long time ago while PC people were fumbling with IRQ’s and DMA settings to get their peripherials to work.

SCSI is easy and Apple CEO Steve Jobs made a good choice to use SCSI attached peripherals for the Mac back in 1984.

What can iSCSI do for you?

So, enough of that.  What can iSCSI and FreeNAS do for you?  What it can do is make a chunk of storage on a network look like a local disk on your PC.  Why would you want to do this?  Keep reading.

In about 15 minutes of my copious free time I was able to get my Windows 7 PC linked up to a chunk of storage on FreeNAS using iSCSI.  As a home user, using iSCSI and FreeNAS you are on your way to a SAN (Storage Area Networks) that are commonly used in large corporate data centers.

Why SAN ?

Why connect real disk to a PC or a server when you can connect storage from a storage pool on a network that looks like local disk to that PC or server?  Here’s why.  Because managing a large storage pool on a network is more cost effective than managing physical disks on a PC or a server.

Central storage can be backed up in a consistent manner.  Storage allocated from a central pool can be dynamically re/allocated to PC”s and servers on demand.  If you need more “local disk” on your PC then why mess with internal physical drives of fixed capacity?  Using SAN you can dynamically allocate any size disk you need and then attach this to your PC or server and have it appear as local.

Attaching real physical disks of fixed size to a serer or PC is so “five minutes ago”.  Storage Area Networks is sometimes a better solution.

Best thing is that FreeNAS and your Windows Vista/7 machine will let you easily mess with iSCSI and experiment with SAN for the cost of a “Clunker”.

FreeNAS and iSCSI

Here is my configuration in pictures – iSCSI to FreeNAS works like a charm.

Click to enlarge and take a good look at this.  Disk 1 (volume name iSCSI) looks like real disk attached to my PC.  It’s not a real disk in the sense of Disk 0 which is real hardware spinning around inside this laptop.  Look over to the right.  The volume iSCSI looks like a hard drive.  It is not a network share like NAS40GB.  FreeNAS is presenting both the network share (NAS4oGB) and the volume iSCSI via iSCSI over my home netowrk.

FreeNAS_iSCSI_1

This Microsoft web page will show you step by step how to connect to iSCSI storage.  The window to the right is the configuration that shows Windows where to find the network storage.  I took all the defaults.

FreeNAS_iSCSI_2

Here is the configuration in FreeNAS.  The 1,000 MB (1GB) volume is just a blob of bits as a file under /mnt/NAS40GB/mySCSI.

FreeNAS_iSCSI_3

Conclusion

Go do.

Resources

http://en.wikipedia.org/wiki/IP_SAN

http://www.freenas.org/index.php?option=com_openwiki&Itemid=30&id=sug:en

iSCSI uses TCP/IP (typically TCP ports 860 and 3260). In essence, iSCSI simply allows two hosts to negotiate and then exchange SCSI commands using IP networks. By doing this iSCSI takes a popular high-performance local storage bus and emulates it over wide-area networks, creating a storage area network (SAN). Unlike some SAN protocols, iSCSI requires no dedicated cabling; it can be run over existing switching and IP infrastructure. As a result, iSCSI is often seen as a low-cost alternative to Fibre Channel, which requires dedicated infrastructure.
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Written by frrl

August 25, 2009 at 6:59 am

9 Responses

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  1. Hi,
    I want to do it the other way around, we have a SAN storage with extra space ad it supports iSCSI, I would like to implement a FreeNAS and I want it to use SAN storage thrugh iSCSI

    Please let me know if you know the answer
    Thank you

    Ibrahim

    January 7, 2013 at 9:04 pm

  2. Travis, one of the advantages of StarWind if compare with OpenFiler is that you can install it on computer which is already running other roles – you can consolidate resources…Furthermore, we are going to release StarWind v5 which will have robust set of features – here’s a link to StarWind v5 preview:
    http://www.starwindsoftware.com/starwind-v5-preview

    Vadim Nekhai

    October 21, 2009 at 8:48 am

  3. Another reason to use FreeNAS, it’s FREE with no limitations, unlike the free version of that Starwind rubbish. Also no need to purchase a copy of Windows! Openfiler is another good free NAS/iSCSI Target solution.

    Travis

    September 24, 2009 at 2:07 am

  4. Hi guys. I see there’s a discussion about FreeNAS and our product, StarWind, right here. Could the author send me an e-mail and I’ll try to tell him the advantages of StarWind?

    Vadim Nekhai

    September 9, 2009 at 3:00 pm

    • I wrote the articles on FreeNAS. I was going to write a review of StarWind.. but… e-mail to you on the way.

      frrl

      September 9, 2009 at 5:17 pm

  5. Great post!
    Only one question – why FreeNAS? There is products, who could give you much more functions, that you can to test and to use. Such developers as Microsoft, LeftHand StarWind are so. It would be interesting to read about them.
    Regards.

    Lubash Zensky

    August 31, 2009 at 1:43 pm

    • Why FreeNAS? Fate. It was just that FreeNAS came to my notice. I gave it a try – and it worked. So I wrote about it.

      I wasn’t even looking for a NAS solution. I wasn’t looking for anything in particuar. FreeNAS passed into view.

      FreeNAS does much more than NAS and iSCSI. I really use it to manage my bit torrents and to provide a SMB share to my windows machines.

      I looked at the others you mention – yes, there is a free version of StarWind. LeftHand looks like it was acquired by HP.

      So perhaps they are all good. It was not my intention to say that FreeNAS was any better than the others – just that it exists.

      Many people who read this blog like to play hands-on with things and learn. So that’s why I put these things out there. To encourage people to try these simple solutions.

      So, with your comment – now they know about 2 more solutions to NAS and iSCSI. Maybe they will try them out and tell others what they discovered.

      If they do try these others out and write a blog of thier own about it they can post a link to that blog here – or write what they found out directly here in the comment box.

      The web is about collaboration and knowledge sharing – right.

      Here are some links to the products you mention. From what I can see – StarWind requires an operating system.

      What I found compelling about FreeNAS is that it requires nothing but a bare machine headed for the trash. No operating system required – boots from a CD; saves config on a USB frash drive; don’t need a monitor, keyboard, or a mouse. My opinion, the ultimate low end, near-zero-cost solution that offers a boatload of features that can be run on a machine that is headed for the landfill. For StarWind, you at least need a pre-installed OS.

      http://www.starwindsoftware.com/free

      http://h18006.www1.hp.com/storage/highlights/lefthandsans.html

      frrl

      August 31, 2009 at 4:40 pm

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