I am not sure which vendors thin provisioning you are talking about, but the 3par Thin Provisioning works fine with Oracle ASM and RAC for ocr, voting and data ASM volumes. Smallest LUN size in 3par is 1gb. From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Andrew Kerber Sent: Monday, November 22, 2010 4:02 PM To: Harel Safra Cc: pnedeljkovich@xxxxxxxxxxxxxxx; Amaral, Rui; oracle-l@xxxxxxxxxxxxx Subject: Re: ASM disk corruption Yup, thats what we did too. Like I said, we never did figure out how it got overwritten. Problem was our smallest possible LUN size was 17G, thats an awful lot of wasted space once you make 3 (or 5) of those. Of course thin provisioning might allow us to work around that eventually, but that seems like a technology that isnt well tested in Oracle clusterware. Anyway, thats kind of OT. I will be really interested to see if the OP can find a cause of the problem. On Mon, Nov 22, 2010 at 2:40 PM, Harel Safra <harel.safra@xxxxxxxxx> wrote: We have a dedicated disk group for ocr/voting that's just 1GB and doesn't contain data files. It made sense (to me at least...) to separate OCR from other data for later database cloning, etc. Harel Safra On 22/11/2010 21:39, Andrew Kerber wrote: MOS recommendation was to use normal or high redundancy instead of external. Like we could waste all that space. -- Andrew W. Kerber 'If at first you dont succeed, dont take up skydiving.'