ASM diskgroup redundancy

From: Mladen Gogala <>
Date: Wed, 7 Sep 2011 13:28:03 +0000 (UTC)
Message-ID: <>

Why would anybody want to use any other redundancy than 'external'? The 'normal' redundancy means that there is 2-way mirroring and 'high' redundancy means that there is 3-way mirroring. My servers are connected to SAN (HP EVA 8000) which does RAID 1+0, RAID-5 or RAID-6, as needed. There is also multipathing enabled, which means that there are 2 HBA's and that if one fails, the other one takes over. Significant investment was made into SAN with all those capabilities, 16G of NVRAM, storage virtualization, snapshots and many other goodies. A consultant is now telling me that I am doing things wrong because I settled for an external redundancy. Also, I keep voting file and OCR on an OCFS2 file system, precisely to avoid the local registry stuff. I am aware of the recommendation to keep everything on ASM but that complicates the install. Oracle licenses are expensive as it is, I have a limited number of CPU cores at my disposal and I have to make the best of it. Why would I need to waste CPU on ASM mirroring when the company has already paid for the device that can do it automatically, with its own CPU?
Received on Wed Sep 07 2011 - 08:28:03 CDT

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