Re: ASM of any significant value when switching to Direct NFS / NetApp / non-RAC?
Date: Tue, 7 Aug 2012 13:34:33 -0400
Message-ID: <CAEgY-F7NCB8GwOjXYxM6+-Od5HRZrKO=tJuKZykPQfB9xubv-Q_at_mail.gmail.com>
Dana,
Perhaps your sysadmins/storage admins are recommending no ASM because of the change from SAN to NAS, not Direct NFS in particular? (I'm not saying the recommendation is good or not good for you or in general, just that I don't see DNFS/ASM overlap).
Whether you use file systems or ASM, DNFS provides a performance improvement over the OS kernel NFS implementation of NFS.
If you are moving from unstriped/non-raid disk to a disk appliance, that probably means ASM striping support is of no interest going forward, but their is more to ASM than that.
That said, I believe ASM is an unnecessary complication for my standalone/non-RAC databases. Your mileage will vary.
Cheers, Wayne
Wayne T Smith - wts_at_maine.edu - UMS-ITS-ECAS -
- "For every action there is an equal and opposite criticism."
On Tue, Aug 7, 2012 at 8:45 AM, Dana Nibby <dananrg_at_yahoo.com> wrote:
> We currently use ASM for all instances on a block storage SAN. The
> sysadmins and storage admins are migrating all 11g instances over to NetApp
> storage with Direct NFS (RHEL on VMWare is in the mix as well--and VMWare
> is new for us; so is SMO). They're strongly advising us to discontinue
> using ASM in this new environment. Their Rationale: no demonstrable value
> worth the complexity of (them) managing ASM; that the ASM functionality
> isn't being used. And that ASM made sense when using a block storage SAN
> environment but not in the new one. "Why would you layer an LVM atop an
> LVM?" they ask. Since we always specify External Redundany for ASM
> diskgroups, etc.
>
> Although I'm certain there is a lot of functionalty crossover, where do
> Direct NFS and ASM capabilities *not* intersect? In other words, can any
> compelling case be made to keep ASM in a NetApp/Direct NFS environment? If
> so, which features of ASM make the case (if there's one to be made). As
> DBAs without root or storage access, will we lose any ability (e.g. file
> mgt) to do things ourselves with Direct NFS that we had with ASM? Would the
> sysadmins and/or storage admins be taking over more of the workload under
> Direct NFS? I certainly don't want to persist something that adds another
> layer of abstraction if there's no clear value--what is implemented must be
> supported. But I want to be sure we DBAs aren't handicapping ourselves
> before we agree to "no more ASM" given the separation the duties, etc.
>
> Anyone here, in a non-RAC environment, continue to use ASM with Direct
> NFS? Though there's evidently no reason why you can't have both,
> I'm wondering what the strongest case there is in favor of using both. And
> what's the strongest case for jettisoning ASM in our new environment? The
> same one already made above?
>
> Best,
>
> Dana
> --
> http://www.freelists.org/webpage/oracle-l
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-- http://www.freelists.org/webpage/oracle-lReceived on Tue Aug 07 2012 - 12:34:33 CDT