Re: [GUSDEV] [Slightly-OT] ASM with Oracle10G

[Michael S. <m...@sa...>]

Hi Josef,

CBIL has been using ASM for about a year now.  It's a new technology, 
and it's not without its pains, so you should be comfortable working 
with the bleeding edge and of course ensure that you have valid backups. 
  Release 2 is much better than Release 1, so make sure you use that 
(i.e. 10gR2).

Having said all of that, ASM is a very cool technology and has a lot of 
appealing promises.  Among those are automatic balancing to address IO 
load, simplified management of files, etc.  As the number of disks and 
nodes you have in your database system increase, the value of ASM increases.

See below for specifics.


Josef Jurek wrote:
> Up to now, we at the Preuss lab have installed and used
> GUS under Oracle9i only.  As we are beginning to install
> Oracle on a new machine (RHEL ES release 4/Linux 2.6.9-22.ELsmp),
> we decided to go with version 10g here.  So far, the only issue
> with this installation has been installing the Automatic Storage
> System or ASM, a new feature to Oracle10g.
> 
> Some questions:
> 
>    Is it worth going to ASM instead of just using the 9i
>    method of managing tablespaces, what the manual calls the
>    "File System" approach?  I suppose I could just
>    start with the File System approach and upgrade to ASM
>    later.

True on this latter point.  Whether it is worth it is highly dependent 
on your setup-- how many nodes and disks?

> 
>    ASM Support Library; the manual calls it "optional" yet
>    "recommended".  Do people find this worth having?
>    As far as I can tell, using the ASMLib means that you cannot
>    run SELinux (Security-Enhanced Linux).  Is this what
>    other people are finding?
> 

As far as I know, ASMLib is required under Linux.  I can't imagine it 
not being there.  CBIL is/was exploring SELinux, but didn't have any 
machines that had it activated.  Migrating to SELinux poses some 
challenges on existing machines since a large number of items can 
potentially break in mysterious ways.

>    Our Linux box already has RAID disks, therefore the manual
>    seems to indicate that the "external redundancy" option for
>    ASM is a way to go as opposed to the "normal redundancy"
>    or "high redundancy" options.  Do people agree?
> 

Yes, this is how CBIL does it-- external redundancy handled by the RAID 
controller.  If you're not using RAID, or don't want to, normal 
redundancy seems like a nice option, but note that it's equivalent to 
RAID 1-- there's no equivalence to RAID 5.

>    Does anyone have any suggestions for other things to
>    watch out for?
> 

Oh, too many to list here :)  If you do do ASM, just watch for 
permissions on the asmdisks under /dev-- oracle:oinstall needs write 
access or you'll get very strange errors.

--Mike

> Thanks; Josef
> 
> 
> 
> Josef Jurek
> 
> Daphne Preuss Laboratory
> Molecular Genetics and Cell Biology
> The University of Chicago
> ju...@cs...
> 
> voice: (773) 702-9559
> fax:   (773) 702-6648
> 
> 
> 
> 
> 
> -------------------------------------------------------
> This SF.Net email is sponsored by xPML, a groundbreaking scripting language
> that extends applications into web and mobile media. Attend the live webcast
> and join the prime developer group breaking into this new coding territory!
> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642
> _______________________________________________
> Gusdev-gusdev mailing list
> Gus...@li...
> https://lists.sourceforge.net/lists/listinfo/gusdev-gusdev