QUERIES : MS MPIO msdsm - Storage

This is a discussion on QUERIES : MS MPIO msdsm - Storage ; good morning: i work for Arystor ( http://www.arystor.com/ ) and our company makes RAID controllers. we have a few questions regarding MPIO from Microsoft. - MSDSM is the Microsoft DSM available in the MPIO DDK. i know that MSDSM is ...

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  1. QUERIES : MS MPIO msdsm

    good morning:

    i work for Arystor (http://www.arystor.com/) and our company makes
    RAID controllers.

    we have a few questions regarding MPIO from Microsoft.
    - MSDSM is the Microsoft DSM available in the MPIO DDK.
    i know that MSDSM is available on Windows 2008 Server.
    we would now like to use MSDSM on Windows 2003 Server.
    is that possible?

    - the MSDSM binary from Windows 2008 Server should work
    as is on Windows 2003 Server. is that correct?

    - according to the license with Microsoft, is Arystor allowed
    to discuss MSDSM, MPIO, and DSM on public forums?

    any information on this will be appreciated.

    have a nice day,

    Aaron
    --
    { tel: +353-21-438-9980; fax: +353-21-488-2915 }

  2. Re: QUERIES : MS MPIO msdsm


    Aaron, response inline:

    ArystorAaron wrote:
    > good morning:
    >
    > i work for Arystor (http://www.arystor.com/) and our company makes
    > RAID controllers.
    >
    > we have a few questions regarding MPIO from Microsoft.
    > - MSDSM is the Microsoft DSM available in the MPIO DDK.
    > i know that MSDSM is available on Windows 2008 Server.
    > we would now like to use MSDSM on Windows 2003 Server.
    > is that possible?


    No, the MSDSM supports both iSCSI and FCP (or other bus protocols) and
    exists in Server 2008 and beyond. Server 2003 does have the Microsoft
    iSCSI DSM available as part of the iSCSI Initiator download. This DSM
    does not support FCP or other bus protocols.

    >
    > - the MSDSM binary from Windows 2008 Server should work
    > as is on Windows 2003 Server. is that correct?


    Nope. You can try, but I don't think it will work, and it definetely
    will not be supported by Microsoft. In addition, I absolutely know that
    MSCS will NOT work if you attempt to use the msdsm on 2003. The
    reason is that MSCS (2003) uses SCSI2 RESERVE/RELEASE and in order to
    perform active/active load balancing the SCSI2 reservations must be
    converted to SCSI3 Persistent Reservations. Server 2008 Failover
    Cluster uses Persistent Reservations natively so the DSM must use
    different logic to handle both cases if it was supported on both
    platforms which the msdsm is not.

    >
    > - according to the license with Microsoft, is Arystor allowed
    > to discuss MSDSM, MPIO, and DSM on public forums?


    Hmmm, good question. Since MPIO is part of the WDK moving forward, I
    suspect that it's OK to discuss since the WDK is generally available to
    the public.

    >
    > any information on this will be appreciated.
    >
    > have a nice day,
    >
    > Aaron
    > --
    > { tel: +353-21-438-9980; fax: +353-21-488-2915 }


  3. Re: QUERIES : MS MPIO msdsm

    good afternoon Kenny, from Carrigtwohill, Ireland:

    On Oct 20, 8:02 pm, Kenny Speer wrote:
    > Aaron, response inline:


    thank you for responding. we are now evaluating your response and
    will reply shortly.

    Aaron P. D'Souza

  4. Re: QUERIES : MS MPIO msdsm

    good evening Kenny:

    i saw your reply to both postings. i am much obliged to you
    for responding so quickly. i am going to respond to your
    other posting also in 1 consolidated personal email.

    btw, i also saw this other posting from you, which was very
    informative. we know you from this posting. 8-)

    Set up MPIO on Windows 2003 and EMC CX300
    http://groups.google.com/group/micro...9026a44acfab1c

    On 20 Oct 2008 20:02, Kenny Speer wrote:
    > On 20 Oct 2008 16:56, ArystorAaron wrote:
    >> MSDSM is the Microsoft DSM available in the MPIO DDK.
    >> i know that MSDSM is available on Windows 2008 Server.
    >> we would now like to use MSDSM on Windows 2003 Server.
    >> is that possible?

    >
    > No, the MSDSM supports both iSCSI and FCP (or other bus
    > protocols) and exists in Server 2008 and beyond. Server
    > 2003 does have the Microsoft iSCSI DSM available as part
    > of the iSCSI Initiator download. This DSM does not
    > support FCP or other bus protocols.


    what i know, from the MPIO Development Kit (MDK) is that
    MSDSM was also available in previous releases of MDK, in
    source code form. we currently use MDK121. MSDSM source
    is also available in MDK118.

    besides that, MDK Release Notes say that MSDSM was fixed
    to work on Windows 2000 in release 1.18.3790.1920.

    that means, MSDSM source in the MDK works on Windows 2000
    also.

    there is nothing in MDK documentation that says that MSDSM
    will not work on Windows Server 2003 (WS3). in fact, if i
    understand correctly, the current MSDSM from MDK is
    supported on all platforms from W2000 to WS3 to WS8.

    note that i am not talking about the binary from WS8. i am
    considering only the MSDSM source from the current MDK.

    >> the MSDSM binary from Windows 2008 Server should work
    >> as is on Windows 2003 Server. is that correct?

    >
    > Nope. You can try, but I don't think it will work, and it
    > definetely will not be supported by Microsoft.


    well, Microsoft (MS) recommends that a vendor code a DSM
    so that the same binary works on different OSs. so, i
    would have expected that MSDSM from WS8 would also work
    on WS3, through backward compatibility. i thought that,
    MSDSM would detect which version it was running on and
    accordingly use features available to it on that platform.

    > In addition, I absolutely know that MSCS will NOT work
    > if you attempt to use the msdsm on 2003.


    do you know this for sure? what about the MSDSM source that
    was available at least from MDK118. i know that in our
    company, we used MDK118 for WS3. i dont think that WS8 was
    available at that time.

    also, current MDK documentation says that MSDSM has been
    fixed to work on Windows 2000 also. so, there would not
    be any SCSI-3 Persistent Reservation (S3PR) at that time.
    ami i correct?

    > The reason is that MSCS (2003) uses SCSI2 RESERVE/RELEASE
    > and in order to perform active/active load balancing the
    > SCSI2 reservations must be converted to SCSI3 Persistent
    > Reservations. Server 2008 Failover Cluster uses
    > Persistent Reservations natively so the DSM must use
    > different logic to handle both cases if it was supported
    > on both platforms which the msdsm is not.


    i understand. a question, in case you know:
    - firstly, MSDSM source was available for WS3 before WS8.
    - secondly, MSDSM was fixed for Win2000.
    - thirdly, i read a bit of the MSDSM code. there is
    code to support S3PR.

    do you think that MSDSM code supports both WS3 SCSI-2
    Reserve/Release (S2RR) as well as S3PR? i see that some
    conversions are done internally, though i am not yet an
    expert to understand fully.

    >> according to the license with Microsoft, is Arystor
    >> allowed to discuss MSDSM, MPIO, and DSM on public forums?

    >
    > Hmmm, good question. Since MPIO is part of the WDK moving


    actually, i would like to clarify. MPIO comes from the MPIO
    Development Kit (MDK) that Microsoft Storage Partners
    (http://www.microsoftstoragepartners.com/) supplies.

    Windows Driver Kit (WDK), on the other hand (otoh), has the
    tools and environment to build a DSM from MDK source. i
    have not seen MPIO in WDK, only in MDK.

    thank you once again,

    Aaron P. D'Souza

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