raw logical volumes and oracle

raw logical volumes and oracle

Post by Daniel Tisseran » Fri, 22 Jan 1999 04:00:00



Does anyone have any experience using raaw logical volumes with oracle or
any reason not to use raw volumes in an HPUX environment?  Is there a
problem spanning multiple drives with a raw logical volume and putting a
tablespace on it?

Thanks,

Daniel

 
 
 

raw logical volumes and oracle

Post by S. P. Pohilk » Fri, 22 Jan 1999 04:00:00


Hi, Daniel!


> Does anyone have any experience using raaw logical volumes with oracle or
> any reason not to use raw volumes in an HPUX environment?  Is there a
> problem spanning multiple drives with a raw logical volume and putting a
> tablespace on it?

We use raw devices on NCR UNIX. I'm not a UNIX guru, but from Oracle point of
view
it works much faster. There are  two drawbacks: NCR doesn't support a raw
device
bigger than 2 GB, and it's not very flexible. And use it only for tablespace,

do not place arch log files on raw devices.

Peter.

 
 
 

raw logical volumes and oracle

Post by Kai Horstman » Wed, 27 Jan 1999 04:00:00



> Does anyone have any experience using raaw logical volumes with oracle or
> any reason not to use raw volumes in an HPUX environment?  Is there a
> problem spanning multiple drives with a raw logical volume and
> putting a tablespace on it?

Hi Daniel

If I remember right, Oracle encourages the use of raw devices on HP-UX.
If you use Logical Volume Groups of HP-UX, you have the flexibility to
extend one logical volume across several physical drives. If you
increase the size of a logical volume, you can increase the tablespace
with ALTER DATABASE DATAFILE '/dev/xxxx' RESIZE ....
Please read the installation guide carefully. There are some hints to
install a kind of cache driver into the kernel for logical volumes.

If you decide to put your tablespaces into the normal file system,
Oracle strongly reccomands that you switch OFF the write back cache and
enable write through to disk.
If you use the HP for other purposes than a pure database server, you
will be punished with a degree of write performance for that.

Good luck
Kai