HP-UX Archives » Musings of an IT Implementor

Oracle on NetApp via NFS (yes, really, NFS!)

I’ve blogged about SAP on HP-UX before, which includes a load of notes and whitepapers about Oracle on HP-UX.
This blog post is about Oracle storage on NetApp.

Here’s a NetApp whitepaper specifically for Oracle on HP-UX, when using NFS mounted partitions from a NetApp device.
You should pay particular attention to ensuring that you have the correct OS patches applied, plus the kernel settings related to NFS should be set. You should also note the section on direct I/O.

This is the HP whitepaper for NFS tuneables but it’s been moved into the new HP site. It looks like it’s possible to get a slightly older version for HP-UX 11iv2 from ManualShark.org here.

I’m currently seeing average Oracle sequential read times of about 5-8ms running over a single gigabit ethernet card.

If at all possible ensure that you test the new architecture before hand (TEST should be representative of PRD!).
Make sure you identify and reduce Oracle full tablescans if possible. Basically reduce I/O as much as possible.
Be prepared to bump up the buffer cache a little if you have the RAM (or the slots for the RAM).

Ensure that your Oracle partitions are seperate partitions and not shared with any other apps, so that you can change the mount point options specifically for Oracle.
Set the Oracle partitions file system block sizes according to Oracle/HP-UX best practice (again, see my other SAP on HP-UX post for more on this).

Most importantly, have your DB tuning team on standby, get those AWR snapshots running more frequently and make use of the ASH reports specifically for tuning SQL statements.

Check if Hyperthreading is enabled in HP-UX 11iv3

UPDATED: Inaccessible links to HP.com have been removed. I couldn’t find the original PDF docs anywhere online any more, so I’ve just removed the links.

You should note that HP-UX 11iv3 enables the default PSET setting for HT by default, but you may still need to enable the firmware setting.
You should also note that HP-UX 11iv2 does not support HT.

All the checks below should return 1 (for enabled).

Check HT is supported in your chipset:
$ getconf _SC_HT_CAPABLE

Check the firmware setting is enabled:
$ getconf _SC_HT_ENABLED

Check the default PSET has HT enabled:
$ kctune -v -q lcpu_attr

Enjoy some HT goodness.

HP OmniBack / DataProtector Version Check

How to tell the version of HP OmniBack / DataProtector client installed on your HP-UX server:


$ /opt/omni/bin/omnicc -ver
HP Data Protector A.06.11: OMNICC, internal build PHSS_41954/PHSS_41955/DPSOL_00442/DPLNX_00148, built on Thu Mar 24 07:14:15 2011

It’s possible to tell if a backup is running by using PS:
$ ps -ef | grep omni
Should show any agents running.

Oracle Storage Sub-system Load Stress Testing

Whilst looking around for an Oracle equivalent stress testing freebie (like SQLIO for SQL Server), I found out about ORION (ORacle I/O Numbers).
It’s been about for a while and can be used to stress test storage systems.
It’s a simple single binary file that generates I/O load on a storage system using Oracle’s I/O call stack.
No need to install Oracle at all!

Unfortunately for me, it only works with file systems that have Async I/O enabled.
I did not, and therefore could not use ORION.
When I finally get time to install Oracle on my new Oracle Enterprise Linux 6.1 environment, I’ll give it a go.

SAP on HP-UX

There are various methods of tuning an SAP system, but sometimes the operating system vendor will permit specific tuning so that the SAP system can take better advantage of the available resources.
Usually, you can find whitpapers on the O/S or hardware vendor’s web site, but also SAP will themselves develop a range of SAP notes that will offer avice and guidance when running on certain approved hardware partners.
If you’re using HP-UX 11iv3 (11.31) and you are running SAP, then here are some gems direct from SAP themselves:

Note:
172747 HP-UX OS Parameter Recommendations
798194 HP-UX async IO trace files
837670 HP-UX OS Patch Requirements
918279 HP-UX SAPOSCOL Versions
1077887 HP-UX filesystem options
1329878 Using non-default pagesize on HP-UX
1351051 Support of Oracle on HPVM
1457063 HP-UX Consolidating SAP Systems
1575609 Future HP-UX support for SAP on Oracle

I would highly recommend the OS Parameters note.
If you’re suffering I/O performance issues, make sure that you have set the correct block size as per 1077887.
A huge (>10%) reduction in memory usage can be obtained following 1329878, but only if you are using Oracle 11g.

Using the direct I/O option alone on a VxFS 5.0 environment decreased Data Protector backup times by over 1 quarter e.g. a 1.5 hour backup reduced to ~1 hour.

I haven’t investigated the HPUX_SCHED_NOAGE O/S parameter option yet (I need the audacity to recommend it to the server team!), but according to this excellent blog post by Christian Bilien, it should help your environment significantly if you’re running more than one Oracle database on a SMP system.
My reasoning is that there will be more than one CPU hungry Oracle thread and they could each be battling against each other (ageing each other out) even more so in a well tuned system with less I/O (large SGA/PGA and well tuned SQL) meaning less voluntary context switches and more forced ones. It’s possible that in this situation, without HPUX_SCHED_NOAGE, you could start to see CPU bottlenecks.

HP also produce their own performance recommendations for running Oracle.
Here’s one on the HP recommended filesystem IO options.
Notice that it says if you’re using VxFS v5.0, you don’t need to worry about 1KB block sizes on Redo and Archive Log partitions.

WARNING: Take heed in the warning about Progress databases on file system partitions with directio enabled on the mount options. I have personally experienced issues where Progress applications have had a 20x decrease in performance! It’s a fact, Progress is not very good without the file system cache.

This one is specific to tuning HP-UX TCP/IP. Very useful if you’re seeing networking bandwidth problems in you environment.

Finally, the HP-UX Performance Cookbook provides an excellent source of information.
I have noticed that some of the SAP Oracle recommended parameters (830576 “Parameter Recommendations for Oracle 10g”) are specific to HP-UX, I have found that a good set of descriptions for some of these are covered in this HP Oracle paper: The Oracle Database on HP Integrity servers.

It’s really a trade off between what SAP say and what Oracle say.
Obviously Oracle know there own database system, so anything Oracle says can also be included.
I generally follow the top down rule, where SAP overrides anything that is contradictory from HP or Oracle, Oracle overrides anything contradictory from HP, and I only implement any parameters from HP if neither Oracle or SAP have anything to say on the matter:
– HP (OS)
– Oracle (RDBMS)
– SAP