Exadata 11.2.3.2.1 NFS Issues – Ksplice Support for Exadata?
When the 11.2.3.2.1 release of the Exadata Storage Server software was released, I was a little excited. There were numerous oneoff patches for the previous release, 11.2.3.2.0, which was the first version to support the Exadata X3, writeback flashcache, run UEK on the X#-2 systems, etc. With that many large changes introduced in one version, it was likely to see some bugs in the .0 release. Fortunately, Oracle was quick to fix many of those issues, but it resulted in several separate patches to update the cellsrv software.
I was working with a colleague last week where we ready to apply this patch to a customer's Exadata system. Everything went off without a hitch - upgrading from 11.2.2.4.2 straight to 11.2.3.2.1. We even applied the patch to the customer's quarter rack in rolling mode, which took under 6 hours to complete. After everything was back up and running, we took an archive log backup using RMAN. For this customer, we back everything up to NFS because it won't fit within the FRA, and they don't want to leave backups inside the production system. We were greeted with a strange error when we tried to kick off the backup job in RMAN:
RMAN> run {
2> ALLOCATE CHANNEL DISK1 DEVICE TYPE DISK;
3> BACKUP DATABASE FORMAT '/mnt/nfs/actest_%U';
4> RELEASE CHANNEL DISK1;
5> }
using target database control file instead of recovery catalog
allocated channel: DISK1
channel DISK1: SID=397 instance=ACTEST1 device type=DISK
Starting backup at 13-02-28 21:38
channel DISK1: starting full datafile backup set
channel DISK1: specifying datafile(s) in backup set
input datafile file number=00007 name=+DATA/actest/datafile/tanel_bigfile.325.808412931
input datafile file number=00006 name=+DATA/actest/datafile/ts_data.380.779860027
input datafile file number=00001 name=+DATA/actest/datafile/system.367.779029515
input datafile file number=00002 name=+DATA/actest/datafile/sysaux.368.779029555
input datafile file number=00003 name=+DATA/actest/datafile/undotbs1.369.779029595
input datafile file number=00004 name=+DATA/actest/datafile/undotbs2.371.779029649
input datafile file number=00005 name=+DATA/actest/datafile/users.372.779029687
channel DISK1: starting piece 1 at 13-02-28 21:38
released channel: DISK1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on DISK1 channel at 02/28/2013 21:38:37
ORA-19504: failed to create file "/mnt/nfs/actest_1jo34pas_1_1"
ORA-27044: unable to write the header block of file
Linux-x86_64 Error: 12: Cannot allocate memory
Additional information: 3 |
It didn't matter what we were trying to back up, just that it was going to NFS. This backup job had worked fine prior to the patch (we took a backup immediately preceding the maintenance window), but we had applied both a database bundle patch (this database was 11.2.0.2) and the latest storage server patch (11.2.3.2.1), which updates the Linux OS to OEL 5.8, as well as introduces the Oracle Unbreakable Enterprise Kernel into the mix.
We checked the mount options to make sure that everything was ok, and saw that it was:
[enkdb01:oracle:ACTEST1] /u01/app/oracle/product/11.2.0.3/dbhome_2/rdbms/lib > mount | grep "/mnt/nfs" 192.168.12.22:/export/nfs on /mnt/nfs type nfs (rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,nfsvers=3,timeo=600,actimeo=0,addr=192.168.12.22) |
After poking around a bit, we opened a service request, which was answered pretty quickly by Oracle support. It turns out that there is a known bug with the NFS driver included in the version of the UEK packaged with 11.2.3.2.1. Oracle provided 3 possible fixes, which I'll detail below. The fixes were:
Oracle Announces Exadata X3-2 and X3-8
Well, it's finally public, so we're able to openly talk about the new Exadata X3 systems. Looking back on my pre-openworld predictions, I was pretty close on a few things. I was correct on the database servers, which will have Xeon E5-2690 CPUs (8 core, 2.9GHz) with 128GB RAM upgradeable to 256GB. It looks like we won't get active/active Infiniband for a while, since the cards in there are staying the same. On the X3-8, the compute nodes are staying the same, for reasons detailed by Kevin Closson a few weeks ago. I also previously blogged about the X3-2 eighth rack. I think this will become one of the more popular options for customers, based on the quarter racks that we're seeing purchased. I'm definitely interested to get my hands on one and see how half of the components have been disabled. It's very cool that Oracle was able to still give the redundancy of a true Exadata in a smaller footprint.
One of the bigger improvements on the X3 series comes down at the storage level. I was a little bit off on the CPUS, which will be E5-2630L (6 core, 2.0GHz) with an upgrade from 24GB to 64GB of RAM. The biggest differences on the storage servers will come via the F40 flash cards, which increase storage 4x (400GB per card), meaning that you'll get 1.6TB of flash per cell. Also, the version of the Exadata storage server software shipping with the X3 systems will be 11.2.3.2.0, which contains the famous "flash for all writes" cache. Disk drives will stay the same (600GB or 3TB).
The new storage server software (11.2.3.2.0) should be released to the public some time this week, and it will include the flash write cache for previous systems. I'm very interested to see what the performance of this feature will look like on the older X2 and V2 systems, where the flash cards are a little bit slower at writes than the new F40 cards. It is worth noting that the write cache feature will be something that users can enable or disable, so if the performance is not what's expected, it can be disabled. Rest assured that once the patch is released, it'll find its way onto one of Enkitec's Exadata shortly thereafter.
Also, this new storage server software release will introduce Oracle's Unbreakable Enterprise Kernel to the 2-socket Exadata crowd. The UEK has been available for the X2-8 systems since their release, but Oracle had yet to run it on X2 systems. This will change with the release of 11.2.3.2.0. It is worth noting that it is still possible to go back to the RedHat compatible kernel if there is adverse performance on the UEK.
That's it for now, and as new things come up during the week, I'll try to post on here.
Exadata X3-2 1/8th Rack
There have been a couple of posts we've seen lately about expectations of an Exadata X3-2 and X3-8 release at Oracle Open World 2012. I mentioned in my previous post about the possible release of an X3-2 1/8th rack configuration. I had guessed that this would be similar to the old V2 basic system that would include one compute node, one storage server, and one infiniband switch - all placed in your own rack. It sounds like I was a little bit off from this original idea.
Oracle has stopped taking orders on X2-2 and X2-8 hardware, and we have had a handful of our customers let us know about emails that they have received from Oracle reps announcing an Exadata X3-2 1/8th rack for sale. This configuration will work as "capacity on demand" (insert salesy buzz words). The plan for the Exadata X3-2 1/8th rack is to contain all of the hardware that exists within a 1/4 rack configuration (2 compute nodes, 3 storage servers, 2 infiniband switches), but to disable half of the CPU cores, half of the flash cards, and half of the hard disks via software controls.
Here's what I would expect this to look like:
- Compute Nodes
- 8 CPU cores (16 threads)
- 128GB RAM
- Storage Servers
- 6 or 8 CPU cores (12 or 16 threads)
- 2 PCIe flash cards
- 6 X 600GB SAS or 3TB SAS hard disks
- 2 Infiniband Switches
This would leave you with either 10Tb or 54TB of raw disk space depending on whether high performance or high capacity drives were chosen. The CPU cores and other hardware components would be disabled using software, probably similar to how unlicensed CPU cores in an ODA are disabled. This would mean that the 1/8th rack configuration would still contain RAC (including RAC licenses), multiple storage servers (only half of the Exadata storage server licenses), and lots of flash cache. The process from upgrading a 1/8 rack to a 1/4 rack system would simply be a matter of enabling the extra hardware, most likely through a license key. Based on the increase in CPU/memory/flash that I'm expecting to see from the X2 --> X3 release, I would expect to see quite a few customers looking at Exadata as an option for many hardware refresh upgrades. It will be really nice to actually test the improvements from the flash write cache that should be announced at Open World as well.
Pre OpenWorld Predictions (Exadata X3-2?)
With only a month away from Larry Ellison's keynote at Oracle OpenWorld 2012, I thought that I would make a couple of wild guesses about new products that may or may not get announced this year. I'll lump them into a few educated guesses and wild conjecture. Insert standard blogging disclaimer (please read this part, Oracle lawyers):
Everything contained in this blog post is pulled from publicly available information and conclusions drawn from products that are currently available outside of Exadata. None of this information comes from within Oracle - not that Oracle would be willing to give me any information otherwise.
Exadata Flash Write-back – Sooner Than We Think?
If you missed Andy Mendelsohn's keynote at E4 last week, you may not have heard the hubbub that surrounded one of his last slides (tweeted by Frits Hooogland here). The mention of the write-back enticed Kevin Closson to talk about the potential ramifications of such a feature. There's a lot of information on that slide to digest (what's a pluggable database? virtualization of database servers?), but I'm going to focus on the flash-based write-back cache. Note that this is not mentioning the "Exadata Smart Flash Log" featured introduced last year with the 11.2.2.4.0 cell patch, discussed by Guy Harrison recently. That feature sends writes to both flash and disk at the same time. In my experience, the disk wins on > 90% of those writes.
This is something larger than just sending writes to flash...an issue that Oracle has likely been working on for a few years. Kevin had mentioned in his post that he expected it to be a feature in the 12.2 release, possibly 12.1 of the database. Because Mendelsohn mentioned that there was a 12-month timeframe for these items, I expected it would occur with the release of the new version of the Oracle database, 12c. I've been doing some poking around in the latest Exadata patch notes and saw a couple of interesting bugs around a write-back cache on Exadata using flash. Bug 14143451 "Enhancement for ASM write-back flash cache resilvering support" and bug 14132953 "Enhanacement to add Write-back flash cache resilvering support" have both been added to the August 2012 bundle patch for 11.2.0.3 (MOS note #1393410.1). If you look at these bugs, you will see that they are currently listed as fixed in 11.2.0.4. The fact that the enhancement has been added to 11.2.0.3 interests me. It looks similar to the introduction of the Exadata smart flash log feature, introduced in the 11.2.2.4.0 Exadata storage server version, released October 2011. If you look through the Exadata bundle patches for 11.2.0.2, you'll see that it was introduced into the database code in bundle patch 9 (MOS note #1314319.1). That bundle patch was released in July 2011. Sound familiar? I wouldn't put it past Oracle to include the write-back cache through a new version of the storage server software.
This sounds like the kind of feature that Larry Ellison would be very happy to announce at Open World in October. We'll just have to wait and see what gets announced. I'll have another post in the next week or so guessing about what may get announced a month from now in San Francisco.
Upgrading the Oracle Database Appliance to Version 2.3.0.0.0
As you may have guessed, applying patches on the Oracle Database Appliance can be a little bit different from your standard Oracle environment. Oracle releases a software version that covers all aspects of the ODA - firmware, operating system, and Oracle software stack (grid infrastructure, rdbms). Versions are numbered like this (image courtesy MOS note #1397680.1:
The ODA was initially released with version 2.1.0.0.0, and has seen several releases over the last year:
| Patch | Features |
|---|---|
| 2.1.0.3.0 | CPU bugfix, 11.2.0.2.5 GI PSU5 |
| 2.1.0.3.1 | OAK software updates |
| 2.2.0.0.0 | 11.2.0.3 GI/RDBMS, OEL 5.8, UEK kernel |
| 2.3.0.0.0 | July 2012 PSU for 11.2.0.2/11.2.0.3, firmware upgrades, multiple database home support |
In this post, we'll discuss upgrading an ODA running RAC or RAC one node to version 2.3.0.0.0. Note that before going to 2.3, users must upgrade to 2.2 first. This is because the 2.3 patch upgrade does not include some of the files used for the OEL 5.8 upgrade, among other things.
Enkitec Extreme Exadata Expo 2012
Enkitec will be hosting the first annual Enkitec Extreme Exadata Expo (E4) this August at the Four Seasons Hotel & Resort in Irving, TX. While I would generally tell people to stay away from Texas in August, this event will definitely be worth it. Enkitec has managed to stockpile some of the greatest minds in the world regarding Exadata and the Oracle database in general. A quick list of some of the speakers:
- Andy Mendelsohn - keynote speaker
- Kerry Osborne
- Tanel Poder
- Jonathan Lewis
- Maria Colgan
- Doug Burns
- Frits Hoogland
- Karen Morton
- Arup Nanda
- Karl Arao
They've even invited a guy named Andy Colvin to come talk about why you shouldn't be scared to patch your Exadata. The list continues to grow, as more speakers should be announced soon. The conference covers 2 days (August 13 - 14), and attendees will have the chance to enroll in one of Enkitec's 2 Exadata courses - Exadata performance optimization, or Exadata Administration (the latter is taught by your's truly).
What's really cool is that if you can't make it to Dallas, Enkitec is offering the chance to attend the conference virtually. I definitely recommend being onsite, as attendees will have great access to the speakers that you won't get virtually. Admission to the conference is $850 for onsite, $500 virtual. I hope to see you there!
Exadata V2 Battery Replacement
For some reason, I've been working on lots of Exadata V2 systems in the past few months. One of the issues that I've been coming across for these clients is a failure in the battery that is used by the RAID controller. It was originally expected for these batteries to last 2 years. Unfortunately, there is a defect in the batteries where they reach their end of life after approximately 18 months. The local Sun reps should have access to a schedule that says when the "regular maintenance" should occur. For one client, it wasn't caught until the batteries had run down completely and the disks were in WriteThrough mode. This can be seen by running MegaCLI64. Here is the output to check the WriteBack/WriteThrough status for 2 different compute nodes (V2 is first, X2-2 is second):
[enkdb01:root] /root > dmidecode -s system-product-name SUN FIRE X4170 SERVER [enkdb01:root] /root > /opt/MegaRAID/MegaCli/MegaCli64 -LDInfo -LALL -aALL | grep "Cache Policy" Default Cache Policy: WriteBack, ReadAheadNone, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteThrough, ReadAheadNone, Direct, No Write Cache if Bad BBU Disk Cache Policy : Disabled |
[root@enkdb03 ~]# dmidecode -s system-product-name SUN FIRE X4170 M2 SERVER [root@enkdb03 ~]# /opt/MegaRAID/MegaCli/MegaCli64 -LDInfo -LALL -aALL | grep "Cache Policy" Default Cache Policy: WriteBack, ReadAheadNone, Direct, No Write Cache if Bad BBU Current Cache Policy: WriteBack, ReadAheadNone, Direct, No Write Cache if Bad BBU Disk Cache Policy : Disabled |
If you have a V2 and you haven't replaced the batteries yet, it's worth running these commands to see what state your RAID controllers are in. To find out what this means for you, read on after the break.
Enkitec Extreme Exadata Expo
Speaking Engagements
Follow me on Twitter
My TweetsTopics
Recent Posts
- Exadata 11.2.3.2.1 NFS Issues – Ksplice Support for Exadata?
- 2013 Presentation Schedule
- Oracle Announces Exadata X3-2 and X3-8
- Exadata X3-2 1/8th Rack
- Pre OpenWorld Predictions (Exadata X3-2?)
Recent Comments
- Andy Colvin on Exadata 11.2.3.2.1 NFS Issues – Ksplice Support for Exadata?
- Andy Colvin on Exadata V2 Battery Replacement
- Renan Medeiros on Exadata 11.2.3.2.1 NFS Issues – Ksplice Support for Exadata?
- Suleman Naeem on Exadata V2 Battery Replacement
- nasmel on Inside the Oracle Database Appliance – Part 1