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Conference smurf::ase

Title:ase
Moderator:SMURF::GROSSO
Created:Thu Jul 29 1993
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2114
Total number of notes:7347

1844.0. "RDR on same disk" by LABC::RU () Fri Jan 24 1997 17:09

    
    When I try to set up two RDR service on the same disk,
    on different partitions, asemgr complains about it.
    
    Is this against the rule?
    
    
    Jason
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1844.1NETRIX::"pelle@zk3.dec.com"pelleFri Jan 24 1997 19:4213
Yes, that is not supported. If you have two different partitions on the same 
disk as DRD disks, they must both be in the same service. 

The reason for this
is that ASE can access a specific disk from one node only. ASE actually
Reserves
the disk on the SCSI bus level, making it impossible for another node to 
access it.  If the two partitions
were in different ASE services you could want to move one of them to another 
node, but not the other. This would be impossible since they MUST be accessed
 from the same node. This is the reason why ASE even doesn't allow that kind
of configuration.
[Posted by WWW Notes gateway]
1844.2LABC::RUThu Jan 30 1997 17:219
    
    I understand now.  But it is hard to justify to let a file - like
    a control file(only couple hundred butes) of Oracle to take the whole
    4 GB disk.  I can't put it into a file system because only raw RDR
    service can be defined.
    
    
    Jason
    
1844.3use LSM volumes!ALFAM7::GOSEJACOBFri Jan 31 1997 08:1615
    re .2
    Of course you don't want to waste a rz29 for an Oracle control file.
    Use LSM to cut the disk into as many small chunks you need.
    
    PITFALL ALARM!
    
    Make sure you use different LSM disk groups! Because if a DRD service
    migrates it drags along the LSM volumes comprising that service and
    that will also drag along the whole LSM disk group those volumes belong
    to and that will migrate all disks with partitions in that LSM disk
    group.
    
    Hope this helps
    
    	Martin