Some ASM questions

Hello Listers,

I am doing a bit of research on ASM and its benfits and drawbacks and was wondering if anyone else has been playing around with ASM. I'd love to have a sandbox to play around and test all these things, but I don't have one available.

I'm curious to know:
- How is extent management handled in ASM databases? I believe the ASM
instance maps the physical drive and extents, but does this take extent management sizing away from the dba? All the ASM online and book examples I am finding are pretty generic with regards to the meat of creating tablespaces/objects inside the ASM diskgroups. I assume it is all local segment and space managed.
- How would extent/object sizing conversions to ASM (adding ASM to an
existing instance or export/import to a new ASM) be handled?
- How does ASM handle blocksizes? I haven't seen an example where
someone tries to use different blocksizes inside an ASM diskgroup. I suppose it becomes irrelevant when using raw devices.
- Are there any quirks using the external redundancy clause? I
wouldn't think so, but I wonder how Oracle would "rebalance" inside the diskgroup with external redundancy.. or is rebalancing "off" when external redundancy is specified, since some volume managers give sysadmins the ability to find/move hot disks?

If anyone can lend some insight, I would appreciate it. //
JK

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