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Oracle 10.2 with ASM and without SG

Schelstraete Bart_1
Frequent Advisor

Oracle 10.2 with ASM and without SG

Hi,

Does anybody has experience in running Oracle 10.2 RAC on HP-UX 11.23 (on IA64) with ASM and without ServiceGuard on a production environment?
(using for example APA and Autopath)

Did you personally encounter problems? Is it stable and performant? Do you advice using ASM or SG with Veritas?
I've seen some white papers, but I want to hear some comments from the 'field'.



4 REPLIES
tom quach_1
Super Advisor

Re: Oracle 10.2 with ASM and without SG

Hello Schelstraete,

i used oracle 9i RAC and Mcserviguard one year ago. when we migrated to 10g, after did some research. i decided dropping MCserviceGuard and instead using 10gR2 CRS. we have 2 nodes cluster running 10.2.0.3 since 10.2.0.1 the cluster have given me some trouble when restarted the nodes but after upgraded to 10.2.0.3 it is much more stable and easy to use than raw devices with ServiceGuard.
so, we are using 10.2.0.3 database, ASM and oracle 10g R2 CRS for more than a year now.
Hope this help!
Thanks,
Tom
Anar
Occasional Visitor

Re: Oracle 10.2 with ASM and without SG

Hi.
Tom, I got a question or rather a bottleneck for a week already installing the RAC on HP-UX 11.23. `netca` fails and `crs_stat -t` shows OFFLINE for the status however I `crs_start` or `crs_stop` them.
What could be missing in regard to listeners?

Thanks in advance.
Bryan Rooney
Frequent Advisor

Re: Oracle 10.2 with ASM and without SG

We're running Oracle 10g R2 (10.2.0.2) Extended Distance RAC over a SONET ring, with each node at a different site (~10 Km). We're running full Oracle stack (DB and Recovery over ASM mirrors) on HP-UX (IA) 11.23 ( B.11.23.0609) w/ patches.

I would recommend starting at Oracle 10.2.0.4 or 11g. ASM has undesirable resilvering "features" at the 10.2.0.2 level and Grid Control has a few issues with RAC at that level as well. We were able to get RAC @ 10.2.0.2 operational, but was many rounds with Oracle support and consulting to get there.
We use HP Autopath (active/active version of securepath) to create multiple paths to the SAN LUNs. For Autopath make sure that only the /hpap/rdsk/hpap# virtual devices or only Auotpath lead devices are visible to ASM (via Oracle asmdiskstring partameter). This resolves failover issues with Autopath, as Autopath only looks to failover to paths it manages. So don't create mknods of the lead or hpap devices or Autopath will not failover failed device paths.
You'll want to track down the HP/Oracle CTC Cookbook for HP-UX RAC (PDF) installs (to big to attach here). It covers all the tested and accepted configurations for HP-UX running Oracle RAC.
HP-UX has Async I/O issues at the 11.23 level and I would go with HP-UX 11i V3 to resolve the Async I/O issues (dropped SAN LUNS can hang Oracle ASM briefly or indefinately depending on patching levels of both products).
To use the third separately located RAC VOTING disk option you'll likely need to use NFS which is supported by HP for HP-UX 11i V3 only, I think.
Overall, disregarding the poor resilvering process and Async I/O issues (both on HP-UX and Oracle 10.2.0.2), ASM has been stable for us. The adding and dropping of LUNs visible to ASM can be done on the fly via ASM which is very attractive to us. One thing to make ure of is to work through the various ways SAN LUNs can fail/disappaer in your ASM diskgroup recovery testing. The documentation on how to correctly recover ASM diskgroups from loss of a SAN LUN is very sparse, at least last I checked.
I'm attching a PDF of ASM setup w/ Autopath.
The devices it refers to in it's asmdiskstring parameter are the lead Autopath devices for each SAN presented LUN.
You can tailor the parameter to make ASM see what you want.

I have not had a chance to verify what the application ASM I/O perfomance is, but our backups via ASM seems to reach maximum throughput (per HP-UX Glance) for 16 paths per LUN or 4 FC ports.
Is you use Async I/O (default for HP-UX Oracle installs), then make sure you verify that you atre configured properly for Async I/O. I think there are Oracle Metalink articles to step you through the checking process.
Bryan Rooney
Frequent Advisor

Re: Oracle 10.2 with ASM and without SG

Attaching PDF to this note