[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference ssdevo::hsz40_product

Title:HSZ40 Product Conference
Moderator:SSDEVO::EDMONDS
Created:Mon Apr 11 1994
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:902
Total number of notes:3319

837.0. "Intel, then Alpha, on same HSZ" by BEET::EAGAN (Among the fashion impaired...) Mon Apr 07 1997 12:31

  I have a customer who's interested in the HSZ50s on WNT for a large 
  amount of storage.  Initially, they're interested in the HSZ connected
  to an Intel box.

  Sometime down the road, they will (hopefully!) be switching to an Alpha
  based WNT system.

  Can they 'just' disconnect the Intel system and connect the Alpha system
  and use the underlying storage?  Yes, the .EXEs (DLLs, applications, etc.)
  would be different... but I'm really referring to the data files
  (shares, etc) that are served out to the user community.

  Or, is there a difference in the way that Intel vs. Alpha actually stores
  the blocks out on the disks.  I seem to remember that there is something
  different between Alpha/Intel re: disk storage -- that's why we can't have
  mixed (Alpha/Intel) WNT Clusters today.

  Cross posted to HSZ40_PRODUCT  &  WINDOWS-NT.
T.RTitleUserPersonal
Name
DateLines
837.1No!JULIET::SMITH_PWed Apr 09 1997 14:2912
    The answer is no, you cannot expect the Intel Data to be there when
    changing to an Alpha.  The main reason it the adapter.  In the Intel
    your are installed on an Adaptec 2944, on Alpha you are connected via a
    KZPSA.  The real reson is the translation above 1GB is not standard so
    adapter use different numbers for the READ CAPACITY command that is
    issued.  All other things will be OK, such as RAIDSETS, MIRRORSETS,
    STRIPESETS.  Just in case this is a working situation, backup the data,
    reconnect to the Alpha and see if the translation works, if the actual
    answer is Yes and everyone is just being conservative, great.  If the
    answer is realy No, then all is OK since a restore can be done.
    
    Paul
837.2MSE1::PCOTEpress one now for personal nameWed Apr 09 1997 21:2217
>    The answer is no, you cannot expect the Intel Data to be there when

     Hmmm. I have an NT cluster with a couple of sables and a mix
     of 2944Ws and KZPSAs. I've reconfigured my storage (hsz/raid
     sets) to use both adapters without incident. No data integrity
     problems.
     

>   The real reson is the translation above 1GB is not standard so
>   adapter use different numbers for the READ CAPACITY command that is
>   issued. 

    I don't understand this. COuld you elaborate please ?

    thanks,
    Paul
837.3MSE1::PCOTEpress one now for personal nameWed Apr 09 1997 21:279
>  the blocks out on the disks.  I seem to remember that there is something
>  different between Alpha/Intel re: disk storage -- that's why we can't have
>  mixed (Alpha/Intel) WNT Clusters today.

   THis is a bug with NTFS concerning transaction log file recovery.
   We (Digital) could support mix architecture clusters if our good
   buddies from Microsoft would cooperate. THe bug was reported about
   two years ago. Glad to see our alliance is working. 
837.4KZPSA and AHA2944 Equal???JULIET::SMITH_PThu Apr 10 1997 12:1811
    The above 1BG translation problems have existed ever since 1+GB disks
    were supported by the various adapter makers.  Originally and still
    today there is no standard Head, cylinder, sector translation method
    available.  For example an Adaptec 2944 will not see a partition made
    on a Buslogic as the same size.  If our KZPSA and the AHA2944 are
    identical (which I doubt) then all is goodness.  If you are running a
    Note .3, if you are runnign and HSZ40 connected to a KZPSA and an
    AHA2944, can both use the others partitions?  I also question this as
    supported.
    
    Paul
837.5MSE1::PCOTEpress one now for personal nameThu Apr 10 1997 12:3321

    So, you're saying that if I create a > 1GB partition using an
    adaptec controller and then replace the controller with a
    buslogic, then I won't be able to see the partition. Is that
    about right ?

    What if the partition 'sits' behind an HSZ. Does this still
    apply ? Note that I've done this many times with kzpsas and
    adaptecs and I am able to see existing partitions. I suspect
    this works because of the HSZ itself. 

    Perhaps if I were using an rz28 in a BA box then I'd have
    the problem you're describing.

    btw, using adaptec controllers on alpha servers connected
    to HSZs is NOT officially supported by storageworks as your
    elluded too but it seems to work just fine.

    Paul

837.6Adapt to Bus vs KZPSAJULIET::SMITH_PThu Apr 10 1997 17:237
    The answer is no, Adaptec partition information cannot be read by a
    Buslogic adapter.  If the KZPSA and the Adaptec can work great. 
    Someone understood this problem and worked out the translation issues.
    
    It's good to here even unsupported configs work as they should.
    
    Paul