Category Archives: Exadata

Category about Oracle Exadata. List of posts.

Exadata version – Part 02

On 08/March/2023 the Oracle Exadata team released version and this include a significant change, OEL 8. I already explained that in my first post that you can read here. Here I will show how to patch to the version for switch and storage cells.


As you know, I am working with Exadata since 2010 and have already posted about how to upgrade to the 19x version,  18.x version, version 12.x (Portuguese only), and many other details for Oracle Engineered Systems. Fortunately, I had the opportunity to apply the 23.1 version over one environment and will show the details.

Here, my environment is:

  • Exadata X6 for storage and dbnodes.
  • InfiniBand Switches.
  • Virtualized configuration (dom0 and domU).
  • dom0 running over version
  • domU running over version
  • Grid Infrastructure running version 19.17.

Since I am running with dom0/domU, my base machine (from where I will call most of the patches) is the dom0. There, I have ssh passwordless/keyless to all other cells, dbnodes, domU, and switches.

Before you start the patch please check the readme for the patch and identify if you have everything in compliance. Do not start any patch if you meet the requirements. Even from a simple database version, grid, and switch versions. And as well, do not start the patch if your machine has HW errors. So, please read the note Exadata System Software Update (32829291) (Doc ID 2772585.1).

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Exadata version – Part 01

On 08/March/2023 the Oracle Exadata team released version and this include a significant change, OEL 8. But is not just that, other interesting requirements are there and I will discuss them below. I will show you how to patch to the 23.1 version and some other details as well. In this first part, I will just discuss one interesting point that you need to take care of before you start to patch. And probably is more important than you imagine.

Before you patch

The new version brings some requirements (over what you need to be running) to allow you to patch. For the Grid Infrastructure, you need to run 19.15 or a newer version. You can even run the 21c (21.6 or newer) version if you want. If you want to know how to do that, I already discussed how to upgrade both in previous posts (19c, and 21c).

For databases, the recommendation is the same, 19c or 21c. You can still run older versions (11,g, 12c, and 18) but they are already (or will be soon) under Market Driver Support. You can read the MOS note over that (here), but to be clear (now) only the 19c have premier support available.

And now things became quite interesting because the new 23.1 version is the first running with OEL 8. And if you check the supplemental README for the 23.1 version just the 19c support the database and GI are listed. So, be aware and check the compatibilities.

One important detail for this version is that you can only upgrade to 23.1 if your base Exadata running version is newer or equal to 21.2.10 (basically one year old only). If not, you need to upgrade to (at least) this version before you patch to 23.1. And this will be the same in the one-year future, it will be only possible to upgrade to 24.x if you will be running (at least) 23.1.

If you are running the old Exadata with InfiniBand, your dom0 will always be updated until Oracle Linux 7 with UEK5. For domU you can upgrade to the OEL 8. And you can upgrade in any order, first dom0 or domU. If you are running RoCE, your dom0 can run the latest OEL 8 UEK6. The blog post from Oracle made an excellent explanation about the upgrade paths and below you can see the images that are there (I used the image from their post).

So, as usual, the version includes everything, switches, storage, and database node. And while for switches and storages, the patches are quite normal, for virtualized environments the upgrades paths start to be a little more challenging to plan. I will explain, but (as hinted in the blog post) the upgrade of the Hosts and Guests independently and in any order. And is hard not because of the patch apply itself, but will be to create the plan. Remember the requirements for Oracle Database and GI? So, you can spend a lot of time patching others parts than the Exadata version.

But let’s put pieces together, the small lines written in several places. With this version 23.1, Oracle is telling you that you need to be running at least the Oracle Database 19c to be allowed to have a continuous upgrade for future releases (and possible usage) of Exadata. And whatever the machine version that you use, IB or RoCE network. You can’t anymore use GI older than 19.15, and the databases are enforced, as well, to be this version too. Imagine that you have some kind of incapability between 11g/12c and OEL 8, if you need to open one SR, you need to have/pay for that support, and will not be cheap.

And if you think the upcoming 23c (and that it will be the new LTS version) being in OEL 8 is a requirement. Imagine one year in the future, when the Exadata 24.x version will arrive, do you think that Oracle still supports 11g to the new OEL 9? I don’t think so.

And by the way, IMHO you should be running to 19c. 11G is from 2009, 12.1 from July 2013. So, they are old and out of support for good reasons. I understand the point that they are working on and the legacy applications that maybe you have. But the point is not just to support them, is the case to be possible to continue to upgrade/update your Exadata. Please do not postpone your database upgrades anymore, for the good sake of your Exadata. 


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Starting with Grid Infrastructure/ASM 19.16 Oracle changed how the REQUIRED_MIRROR_FREE_MB is calculated and the impact is more than expected. Check below examples of the changes, and how this will impact you. This is valid for all GI/ASM starting with 19.16 and only for Exadata/ExaCC.


The REQUIRED_MIRROR_FREE_MB (according to 19c documentation) is:

amount of space that must be available in a disk group to restore full redundancy after the worst failure that can be tolerated by the disk group without adding additional storage. This requirement ensures that there are sufficient failure groups to restore redundancy”.

And (at Exadata environment until 19.16) is calculated based on the disk redundancy that you have. If you choose the HIGH, the raw size of two disks (the largest in your diskgroup) is reserved; at NORMAL, is the raw size of one disk. At Exadata, it differs from other environments because does not consider the whole failgroup failure and the way that extends are written/spread (more info below and in another post).

But for now, understand that the required size is what you need to reserve (as raw space) at your diskgroup to ensure protection in case of disk failure. And it is directly related to the USABLE_FILE_MB because the space that you can allocate at your diskgroup (USABLE_FILE_MB) comes from (FREE_MB- REQUIRED_MIRROR_FREE_MB)/redundancy factor (3 for HIGH, 2 for NORMAL). So, when you increase the REQUIRED_MIRROR_FREE_MB you reduce the USABLE_FILE_MB. I will explain more later.

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Oracle Engineered Systems since 2010

Recently I made a tweet about a new project with Oracle Engineered System (X9M) that remembered me about what I made with these systems until now. So, this opened the opportunity to tell my background and history until now working with these systems. Is not a show-off of ego boost post.


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Upgrade AHF and TFA at Exadata

Quick post for today. Recently needed to upgrade to the last version of Autonomous Health Framework (AHF) from an Exadata running GI 19.5. In this particular case the GI was not even running AHF, but still using the standalone TFA that comes with it. So, here I will show how to upgrade to the last version of AHF and replacing the TFA as well.

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Fixing Exadata Missing Volumes at LVM

Recently during the Exadata patch, one database node reported an issue during the patchmgr and stopped the patch apply. The error was related to missing volumes (LVDoNotRemoveOrUse) at LVM. During the post, you can check the error, but please take attention that it changes some LVM config file contents. So, check correctly the step executed and (if possible) open pro-active SR to be sure what you will be doing.

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Exadata, dracut and LVM locking_type as read-only

Sometimes even a perfectly running server can pass over issues after a simple reboot. And was exactly that occurred recently with one Exadata database node. And was not the first time that the same error appears (and since there is no well-documented step by step to fix it I documented them below). So, check how to fix the issue related to the read-only locking_type of LVM detected by dracut.

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Patching OCW for OH

If you search around about how to patch Oracle Database you will find a lot of blog posts teaching how to patch your Oracle Home (OH) (I will not put the list here because it will be enormous – but just follow Mike Dietrich). But most of them write nothing about OCW, how to patch it, or if it is needed to patch OCW.  And unfortunately, even Oracle is not clear about that.

Just to complement, recently Liron Amitzi got one issue related to OCW. And if you search more, you will find that Frits Hoogland wrote something about it too. But in the end, need I to concern about OCW? And, what is OCW?


OCW means Oracle Clusterware, and basically is the core for the Grid Infrastructure, it is everything there. But for OH is important too because if the database needs to communicate with GI Clusterware it uses the OCW binaries/libraries that are at OH (like srvctl, crstctl) to do that. So, if have some kind of bug at this portion of OCW, it needs to be patched.

The point is that the only place that you can find the OCW patch is under the GI RU patch. Look at the readme for last GI RU (Patch 31305339):

And if you look at the readme for DB RU (Patch 31281355) there is no reference to the OCW patch. So, if apply just the DB RU the OCW will not be updated.

And just to remember you that patch 31305087 does not exist alone to be downloaded:

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ZDLRA + MAA, Protection for Platinum Architecture

The Platinum architecture is the last defined at MAA references and is the highest level of protection that you can achieve for MAA. It goes beyond the Gold protection (that I explained in my previous post) and you can have application continuity even version upgrade for your database.

The image above was taken from

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ZDLRA + MAA, Protection for Gold Architecture

The Gold architecture for MAA is used to emphasis the application continuity. All the possible outages (planned or no) are protected by Oracle features. Here we are one step further and start to design using multi-site architecture. Data Guard, RAC, Oracle Clusterware, everything is there. But even with these, ZDLRA is still needed to allow complete protection.

The image above taken from

With the MAA references, we have the blueprints and highlights how to protect them since the standalone/single instance until the multiple site database. But for Gold we are beyond RPO and RTO, they are important but application continuity and data continuity join to complete the whole picture.

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