Re: raw devices

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 Tue Aug 17 1999 - 14:18:03 CDT