Cellcli can lie to you…

Yes that is true, i said it, cellcli can lie to you there are some special cases were the output of cellcli is not the reality and you should double check it’s output with your standard OS tools. So this the output if dcli calling cellcli on an Exadata rack from an client:

[root@dm01db01 ~]# dcli -g cell_group -l root cellcli -e list cell attributes cellsrvStatus,msStatus,rsStatus
dm01cel01: running       running         running
dm01cel02: running       running         running
dm01cel03:  (more...)

SCAN VIP Troubleshooting

We had a client that was running into a strange issue on their Exadata where new connections coming in through the SCAN were failing.  After doing some troubleshooting, it was discovered that it was related to one of the SCAN listeners not properly accepting requests from new sessions.  The VIP and listener were running, and everything looked normal.

We had the following SCAN setup:

2 (more...)

Kdump to NFS in UEK (Solution)

I’ve previously written about a problem I encountered when kdump is configured to write to an NFS location with UEK (in Exadata software version I’m please to report that the root cause of the problem has been identified and there is a very simple workaround.

There were some frustrating times working this particular SR, the most notable being a response that was effectively, “It works for me (and so I’ll (more...)

Using SSD for a temp tablespace on Exadata

I seem to be getting a lot of surprising performance results lately on our X-2 quarter rack Exadata system, which is good – the result you don’t expect is the one that teaches you something new.

This time, I was looking at using a temporary tablespace based on flash disks (more...)

Exadata Storage Server Version Released

Oracle has released the much-anticipated version of cellsrv compatible with Oracle Database (patch #16980054). Before thinking about upgrading, read MOS note #1571789.1 carefully.  Unless you are planning to run database 12c on your Exadata, it would be advisable to continue down the 11.2 branch (more...)

Oracle Announces Exadata X4-2

Today, Oracle announced the Exadata X4-2 model.  The X4 has some considerable improvements, namely:

  • 12-core Intel Xeon e5-2697 CPUs, up from the 8-core models found in the X3-2 (hello, database licenses!)
  • 256GB RAM per database server, upgradeable to 512GB
  • 96GB RAM per storage server
  • 800GB Sun Flash F80 cards (more...)

Exadata MAA Presentation – Oracle Day 2013 Istanbul

Exadata Maximum Availability Architecture from Yunus Emre Baransel

Kdump to NFS Broken in UEK

There were problems that affected UEK and NFS when was initially released (as covered by Andy Colvin). As mentioned in the comments of Andy’s post: Oracle released an updated ISO with fixes for this problem (patch 16432033).

There were also problems with kdump not (more...)

Info about Exadata’s imageinfo and rpm’s

Recently we noticed that imageinfo was displaying the following information at a customers site. Imageinfo was not displaying data i suspected, so a quick little blogpost about what was going on there.

[root@dm01db01 ~]# dcli -g /opt/oracle.SupportTools/onecommand/dbs_group -l root "imageinfo | grep 'Image version'"
dm01db01: Image version: 11.2. (more...)

Exadata – a new learning cuvrve

Perhaps I might be touch late on adopting/exploring/reacting/coping up with the exadata, but, it was always my dream and passion to work with the technologies since the announcement. As we knew Exadata is not something we can download and configure that easily on PC like those of traditional database or (more...)

About cellcli calibrate

With cellcli you can run the calibrate command, this will measure the performance of your harddisks and flashcards. It will eventually report to you the throughput and amount of IOPS that was measured during the calibrate, it will also report to you which luns are not performing up to par.


Stuck Timezone Upgrades and Smart Scans

I heard a strange report from a client late last week - they weren't getting any smart scans on their Exadata - a data warehouse, no less (and we checked to see if cell_offload_processing was set to true).  Queries would run normally, but for some reason, the "cell physical IO (more...)

Analyzing page allocation failures on Exadata

I have seen several clients who are struggling to decode page allocation failures on Exadata, in this post i will try to explain how to read the backtrace. The following is an anonymized client case where page allocation failures are leading up to a node reboot.

Jan 1 11:58:02 dm01db01  (more...)

Patching an Exadata Compute Node

An Oracle Exadata Full Rack consists of 8 DB compute nodes. Oracle has shifted the strategy to patching the exadata in onwards to using Yum as the method of patching. the Quarterly Full Stack  does not include the DB Compute nodes patches anymore. So that (more...)

Speaking at E4 2013! … and some Exadata Patents good stuff

I’ll be co-speaking with Tyler Muth at E4  and we will be talking about Performance Visualization… some of you may already know that I’m really a big fan of Tableau and just to give you an example on what the tool can do I’ve consolidated all the different viz that (more...)

Slides and Offline Recording of my NYOUG Webinar

I have announced my webinar on Oracle ZFS Storage Appliance for Exadata Backup & Recovery in NYOUG DBA webinar series. You can download webinar slides and voice recod from NYOUG web site

NYOUG SIG Webinar: Oracle ZFS Storage Appliance for Exadata Backup & Recovery

In Friday December 14, 2012 at 12:00 PM -1:00 PM EDT I will be giving a webinar for NYOUG SIG with the following abstract
When it comes to the backup and recovery infrastructure of the Exadata Database Machine, conventional solutions often have only limited performance to keep up with Exadata throughput, whereas Oracle ZFS Storage Appliance can be configured as a very fast, capable, and easy-to-manage backup and recovery solution for any Exadata environment. In this session Husnu Sensoy will describe some of the configuration possibilities of the ZFS Storage Appliance to create a flexible backup and recovery environment for Exadata, (more...)

Scripted Collection of OS Watcher Files on Exadata

| Nov 2, 2012
I’ve been working a lot with graphing DB and OS metrics in R. I find it especially useful in Exadata POVs (proof of value) to gather and graph the oswatcher vmstat files for the compute nodes and iostat for the cells. For an example, take a look at this graph (PDF, 168 KB) of what [...]

Exadata Flash Cache WriteBack

With the announcement Exadata X3, Oracle has introduced a new feature called “FlashCache Writeback” to allow writes to cell Flash Cache (aka Exadata Smart FlashCache) in WriteBack mode. Earlier with WriteThrough mode, writes were not written to FlashCache, instead they were written directly to cell disks. Exadata software used to decide whether to cache these writes back into FlashCache or not. In WriteBack mode, writes are written to cell FlashCache and acknowledgement is given back to calling process as soon as data is written to flashcache. Exadata Server software de-stages the dirty writes in flashcache to spinning disks in the (more...)

Speaking at Enkitec Extreme Exadata Expo

| Aug 9, 2012
I’ll be speaking at the Enkitec Extreme Exadata Expo (E4), August 13-14 in Dallas Texas (you can also attend virtually). They’ve recruited some of the top names from community including keynote speaker Andrew Mendelsohn, Arup Nanda, Cary Millsap, Jonathan Lewis, Karen Morton, Maria Colgan, Kerry Osborne and Tanel Põder. I left a lot of names off the list, many of which you probably [...]