Re: Anyone use the Automatic Shared Memory Management in 10g

dominica_at_gmail.com wrote:
>
> I am planning to upgrade(migrate) from oracle (32bit ,solaris)
> 8.1.7.4 to oracle 64 bits 10g sometimes soon.
>
> Just curious whether anyone using 10g on a unix system and
> using the new "Automatic Shared Memory Management" and
> any thought on it.
>

ASM is in essense just another type of Logical Volume Manager (LVM) - just with a very specific Oracle focus. It can do RAID10 for you, support external redudancy (e.g. hardware RAID10 that requires no s/w "interference"), provides features such as moving data files from one volume to another with the database up and running, and so on.

ASM is not without problems to get to work (I've run into some real humdingers with the ASM kernel module - thank the gods for Metalink that usually contains the answer if you prepared to do some deep and hard digging). Also ASM on some platforms has a problem with multi-i/o path disks (e.g. 2 fibre channels which means each raw slice on the SAN is seen as 3 devices - one per channel and a 3rd load balancing device using both channels). So make sure of any potential issues before the time and what the resolution or work-arounds are.

But once setup ASM does make the DBA's life a lot easier. Was a bit hesitant to use it for starters (after using other LVMs and s/w like Powerpath), but the more I use it, the more I like it.

> Running good in performance or not that good ??

Basic I/O performance is a direct function of hardware (e.g. size of I/O pipe, number of pipes, number of disk controllers, speed of disk controllers, h/w RAID implementation, etc). ASM does not change that, nor can make that faster or slower.

--
Billy