Re: raw devices

Hello,
Thanks Jonathan. I have a better picture now. By using the oflag set this way, Oracle makes the integrity problem disappear, leaving only the speed problem. The problem was that on the Sybase side the mantra is use raw devices for integrity reasons. Probably they use another setting, eliminating the speed problem.
And thanks for your web site. I bookmarked it.

I continue to apologies for my fake e-mail address but this is the best way I found to combat spam.

Jonathan Lewis wrote:

> An important point:
>
> Oracle ALWAYS writes with the relevant 'SYNC' flag set -
> which means that it writes through the file-system cache.
>
> There is no extra risk of lost data between file system
> and raw device.
>
> BTW - such things as 'raid 10' can be defined at a level
> beneath logical volumes and file systems - having defined
> a logical device that spans a number of physical devices
> you can choose to impose a file system on it, or a 'raw'
> volume - depends whether you are using Veritas file system
> or Veritas volume manager on your Sun.
>
> Watch out for number of devices in the stripe, by the way,
> and the location of the mirror-logging section (I've forgotten
> the correct technical name). The former can have a serious
> impact on recovery, the latter can have a serious impact
> on performance (and on disaster recovery if you don't use it).
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> DM wrote in message <37B9AE39.FD337DAD_at_auto.com>...
> >Hi Jerry,
> >Thanks for answering. What I was refering to was some sort of raid 10
> >that you can construct on Solaris at the software level. And from the
> >documentation we inferred that this is safer than the file system. And I
> >still think it's true(you didn't contradict me either).It's also true
> >that you can get a false sense of security by buying expensive raid and
> >ups and placing your server in a room with lots of sprinklers.
Received on Wed Aug 18 1999 - 09:21:51 CDT