Oracle ASM, SAN and VMware

[jpl0000]

Hello,

I have a question about using Oracle ASM. If I only have one physical SAN disk (2 disks mirrored) isolated for an Oracle VM is there any point in implementing ASM in the VMs filesystem by creating multiple virtual disks to support ASM if any IO is still really only accessing one physical disk? This is the first time I will have to do an Oracle VM install and I want to make sure the DBAs have the right info for setting up the DB.

I see that it is tip #14 in the Essentiual Deployment tips doc to use Oracle ASM but it doesn't say anything about assumptions...eg: Is there more than one physical disk available? I am thinking the DBA doesn't want to bother with ASM as there is only one physical disk under this VM but we are in a virtual world now and I don't think the same that would be true for a physical server is necessarily the case for a virtual one.

Thanks

[Josh26]

Hi,

ASM gives you several other benefits.

It improves the filesystem overhead over ext3, and deals with having to concern yourself about file paths. Most Oracle documents will assume you have ASM - I think it's worth it.

[jpl0000]

I'll be using Solaris 10 (UFS) for the OS. Still worth it? And what about the one disk question? If I'm only using one disk is it still worth it? I thought ASM was a way to separate disk IO which doesn't make much sense if there is only one underlying physical disk. I could be way off not being an oracle expert. It isn't a gigantic DB by any means (less than 100mb) either so are there still benefits when using in a VM?

[hjnorris · Accepted solution]

You have only one disk and a 100Mb database?   In this case, ASM is probably an extra layer of complexity that you do not need.

ASM is best suited for spreading data across many, many spindles and in cases where database space management is a consideration.