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Matthew Thomas4
Level 2 (425 points)

Q: Using Pegasus as LUN via a SANLink

Hi,

 

My company currently is using MetaSAN with a fairly complex dynamic drive system from Compellant.  The reliablity of the drive system has been good, but the peformance and cost/performance ratio is not ideal for Multimedia production.   The Compellant drives are simply not designed for AV frame-based data transfer, and it at times, the MetaSAN system can be very touch with sytem updates and licensing, and endless issues with binding to our AD servers.  We also shouldn't need to use 15,000 RPM drives for the HD video production (mostly ProRes), but due to the way the Compellant architecture is setup, this is necessary.  That makes upgrading our storage very expensive especially since the bulk of our storage needs are simple footage that is better suited for larger, cheaper SATA drives. 

 

With XSAN licenses included with OSX Lion now and the advent of the new Thunderbolt SANLINK devices which allow Laptops and iMacs to join the SAN at a reasonable cost, we are considering a move back to XSAN from MetaSAN.  But we cannot do this on the main Drive system initially since the Compellant is being used for more than just our AV department.

 

I want to experiement with a small short-term xSAN to test with our Laptops, etc and try various configurations before making any changes to our large Enterprise systems, but have little budget to do such tasks, hardware-wise.  All of our current fibre RAIDS are being utilized by the live servers, and I can't currently budget a $15,000 Vtrak LUN box just for this process.

 

One option I would like to explore is using a Pegasus Thunderbolt RAID box attached to a SANLINK, which should automatically convert it to a LUN visible to my existing XSAN network. I might be able to setup MetaData on a separate box connected to a similar Pegasus, or even a simple Lacie Thunderbolt drive in Mirrored mode also connected via a SAN Link. The Pegasus LUN and MetaDATA LUN  would connect to an older Brocade 3200 switch which I'll likely leave open (unmanaged) to simplify the test. MacMini MDC's will also be connected via SANLinks and use a separate MetaDATA network utilizing the 1000Base Ethernet for the private network, and a simple USB-Ethernet adapter for public and administration.

 

Has anyone tried using a Pegasus RAID as a LUN?  It is relatively affordable compared to most other high performance Fibre storage solutions to with only a $2000 USD 12TB RAID and an $800 USD SANLINK.  I understand there are downsides to having a consumer-oriented LUN attached to the SAN, and for the purpose I've described, it should be reliable enough.  My main question is whether the SANLink allow it to appear as a LUN, or will it show up as just another HBA.  If this works, this could also make a very good bulk storage LUN option for my AV backups.

 

The SANLINK is apparently driverless - and is platform or computer agnostic, which suggests that it may not only function as an HBA for connected laptops (as it is currently being marketed) but also as a LUN node if necessary.  Anyone Tried this?  If so, any tips woudl be appreciated.

Posted on Dec 3, 2011 8:53 PM

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Matthew Thomas4

Q: Using Pegasus as LUN via a SANLink

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  • by receng,

    receng receng Dec 5, 2011 7:54 AM in response to Matthew Thomas4
    Level 1 (20 points)
    Dec 5, 2011 7:54 AM in response to Matthew Thomas4

    This got me a little confused at first, but I see:

    You want to use the SANLINK to make the Pegasus work as a Fiber Channel Storage.

    This would be very interesting if it worked. I would be surprised if it did - I expect the SANLINK to work as an HBA since Thunderbolt is PCI based.

     

    An interesting test would be connecting two SANLINKS via fiber between a Mac and a thunderbolt drive.

  • by Strontium90,

    Strontium90 Strontium90 Dec 5, 2011 10:06 AM in response to Matthew Thomas4
    Level 5 (4,087 points)
    Servers Enterprise
    Dec 5, 2011 10:06 AM in response to Matthew Thomas4

    Unless the production release of the SanLINK is different, you can not do what you are thinking.  The SanLINK only works in one direction... presenting FC storage to a Thunderbolt host.  You will not be able to present Thunderbolt storage to a FC fabric.

    One option I would like to explore is using a Pegasus Thunderbolt RAID box attached to a SANLINK, which should automatically convert it to a LUN visible to my existing XSAN network. I might be able to setup MetaData on a separate box connected to a similar Pegasus, or even a simple Lacie Thunderbolt drive in Mirrored mode also connected via a SAN Link. The Pegasus LUN and MetaDATA LUN  would connect to an older Brocade 3200 switch which I'll likely leave open (unmanaged) to simplify the test. MacMini MDC's will also be connected via SANLinks and use a separate MetaDATA network utilizing the 1000Base Ethernet for the private network, and a simple USB-Ethernet adapter for public and administration.

     

    Has anyone tried using a Pegasus RAID as a LUN?  It is relatively affordable compared to most other high performance Fibre storage solutions to with only a $2000 USD 12TB RAID and an $800 USD SANLINK.  I understand there are downsides to having a consumer-oriented LUN attached to the SAN, and for the purpose I've described, it should be reliable enough.  My main question is whether the SANLink allow it to appear as a LUN, or will it show up as just another HBA.  If this works, this could also make a very good bulk storage LUN option for my AV backups.

     

    The SANLINK is apparently driverless - and is platform or computer agnostic, which suggests that it may not only function as an HBA for connected laptops (as it is currently being marketed) but also as a LUN node if necessary.  Anyone Tried this?  If so, any tips woudl be appreciated.

     

    Now, keep in mind that this does not mean you can not make a SAN on the cheap using the Pegasus arrays.  All you need to do is use cvlabel to label the LUN(s) and then you can make a SAN.  But, this can only be for testing purposes.  Recall that there is no such thing as a Thunderbolt swtich (analogous to an FC switch) so you can only have direct attached connection.  This means that you can test out the SAN performance on a single controller but never be able to mount the volume on another client. 

     

    Sadly, while both the Pegasus and SANLink are interesting and promising products (pun intended), they can not supplant the traditional components of Xsan.  At least not yet.  I believe there is a place in the future where Thunderbolt will replace or compete with FC.  But for now, Thunderbolt is just fast direct attached storage.

     

    Hope this helps.  I think I have a production SANLink.  Will try going in the other direction when back in the lab.