(NOTE: This is a continuation of a previous question on 4/23/01) Thank you for your response. It confirms my suspicions. While Oracle software installation on shared storage will work, it is more complicated. I will install locally. To wrap this up, can you please extend your response to include the following questions? It should not take much of your time. Again, OPS is not employed.
- What makes the Oracle Software so unique such that installing on Oracle Home on shared storage vs. local storage is problematic; while placing all files associated with a database (control, data, index, redo log, RBS, SYSTEM, TEMP) on shared storage is ok - to the point that Oracle does not recommend/support?
- Would you recommend placing custom code (e.g., Pro*C executables, Dev/2k Forms/Reports executables) on local storage on each node in the cluster or on shared storage? These applications interface databases that will be housed on the shared storage/RAID.
- Can/should the archive destination specification for all RAID-stored databases for which archiving is enabled be on local or shared storage; i.e., either is equally ok - or should the Archive Destination definitely be specified to be on the shared storage? Same question for the Duplex Archive Dest. Should that be employed?
- Finally, on-line backups are sent to on-line storage before output to an off-line tape subsystem. In a shared storage config., where would you suggest they be targeted - shared storage or local storage?
One of the problems is that when your database is running, Oracle places a file in the $ORACLE_HOME/dbs directory. For Oracle 7 & 8, this file is sgadef_sid_.dbf and for Oracle 8i, this is lk_sid_.dbf where _sid_ is your database identifier. This file signifies to many oracle tools and processes that the database is up and running. Any network problems on your network drives may mean that this file can not be found. If it can not be found and the database is up and running, then there are problems.
The other reason that this option is not supported is that Oracle Corp. has not a chance to debug and test every shared storage environment out there. Rather than trying to fix very difficult problems of this nature, they choose not to support this architecture. But I have heard that Oracle is working on this architecture with at least one hardware vendor, Compaq.
Personally, I'd place the code on each local system. That way, network glitches or outages will not affect your application running locally on the server.
Personally, I'd make sure that my primary, and mandatory, archive destination is local. If you want to use multiple archive destinations, then go ahead and make the other destinations on shared storage. But I would not make these destinations mandatory in my LOG_ARCHIVE_DESTn parameter. What happens if the shared storage is unavailable or there is a network problem? If this destination is mandatory, then your database may halt until it can complete all of its archival of the online redo logs.
Backups can really go anywhere. But if you are worried about network problems interfering with anything else, then it goes to reason that one would want to backup to a local storage first, and then move to shared storage. But this is not an absolute. I keep multiple generations of backups around. So if I lose last night's backups, I'm not too worried because I can go back to the previous night's backup. So you can backup directly to shared storage if this is your line of reasoning.
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