Re: Raw Partitions and Oracle

John Bishop wrote in message <35048AAE.B28DEABA_at_atl.mediaone.net>...
>I'm curious to see how many folks are actually running raw vs. file. In
 the
>DBA class I went to I was given a doc stating that running raw is more of a
>hassle for backups (i.e. using dd instead of tar, cp...) and the the raw
 idea
>(unless you are using a third party backup tool because of limitations with
>dd) really is not worth it.

We're running raw, but it is a requirement for running OPS across several nodes. And yes, backups were a bitch. And the method that was recommended (to which we object strongly) was a failure as we had a hardware crash and the backups did not work. Now we're using a 3rd party tool instead of relying on dd and cpio.

>In other words the doc pretty much stated that the peformance gains really
 do
>NOT merit the limitations associated with raw.

Partially true. But then a 1% or 2% increase in performance adds up when you're running large databases - and it can make a difference. However I don't think that using raw devices should be used if the -only- reason is trying to improve disk thru-put performance.

>Seems to me they stated that you should spend more time tuning the appl. or
>looking at SQL rather than messing around with raw.

It's not a question about messing around with raw devices. The problem is that not many Oracle DBAs have the Unix skills to work with and look after raw devices - and that's IMHO why raw devices is considered "problematic".

The only problem I have with raw devices is that there are space overheads. On a 1GB raw device I can get Oracle to only use the first 980MB. And if you run a large database then you have a couple of GBs of raw space that you can not use.

>Any feedback?

Yeah, the voices in my head have stopped shouting and are whispering. Should I be worried?

regards,
Billy Received on Mon Mar 09 1998 - 00:00:00 CST