I decided this week to be a little brave and upgrade one of the Enkitec Exadata racks to 184.108.40.206. I installed the 220.127.116.11.0 Exadata image a few weeks ago, and have been waiting for a chance to upgrade clusterware to 12.2. Thankfully, Oracle provides a very good note for this, but I did hit one large snag that should be documented.
The process for upgrading GI to 12.2 (more...)
Here’s a quick post to help with LUN, SAN or File migration when using Oracle ASM.
Please note that this is just an example method, and it not a definitive guide.
You need to ensure your approach is appropriate for your environment.
Did you know that you can add and drop disks on a diskgroup in a single command.
This saves Oracle from doing 2 REBAL actions and speeds things up considerably using a lot (more...)
This blog post is more of a note for myself on configuring ASMLib.
ASMLib is an optional utility that can be used on Linux systems to manage Oracle ASM devices.
ASMLib consists of the following components:
An open source (GPL) kernel module package: kmod-oracleasm
An open source (GPL) utilities package: oracleasm-support
A closed source (proprietary) library package: oracleasmlib
On my Oracle VMBox, I performed the below steps –
1. Check the installed packages related to (more...)
Deployment of Exadata requires you to generate configuration using Oracle Exadata Deployment Assistant (OEDA). Within the same the default ASM disk groups names are DBFS_DG, RECOC1 and DATAC1. I usually change those to RECO01 and DATA01 as others doesn’t make sense to me and the only place where I find the default ones is on Exadata.
I had an incident last year where the Exadata deployed half way through and names were left by default (more...)
The Oracle ASMFD (Filter Driver) was introduced in Oracle Database 18.104.22.168 and as of the moment it is available on Linux systems only.
Oracle ASM Filter Driver is a kernel module very much like the ASMLIB that resides in the I/O path of the Oracle ASM disks. It provides an interface between the Oracle binaries and the underlying operating environment.
Here are some of the features of ASMFD:
I had the pleasure of rebuilding an Exadata rack for a customer a while back, and it provided a pretty good refresher in backup and recovery for me. As DBAs, we back up databases all the time, but the restores are performed much less frequently. In the case of this rack, there were several databases across multiple ASM diskgroups. One of the goals of the rebuild was to consolidate all of the databases into a (more...)
Few days ago I saw great post from Norman Dunbar
on how to fix a broken ASM spfile.
With version 11gR2 ASM spfile can be stored in ASM diskgroup and by default Oracle Installer will put it there. So if you want to create pfile from spfile your ASM instance should be up and running.
If you have incorrect parameter in ASM spfile which is blocking ASM to start than you have slight problem. You (more...)
Imagine you have 11gR2 Oracle Restart configuration with database files located in ASM.
After server crash you realized that local disks are corrupted and with local disks you lost all Oracle installations. Even though this is important system you don’t have database backup (always take backups!).
But you managed to save all ASM disks as they were located on separate storage.
This will be small beginner guide on how to help yourself in such (more...)
Oracle Flex ASM was introduced in 12c version. This is one of the best features introduced with new version in my opinion.
I won’t speak in detail about Flex ASM because you can find more information in documentation. In this post I will concentrate on how Flex ASM handles crash of ASM instance.
For this test I’ve created 2 node cluster - 12c Grid Infrastructure with Flex ASM enabled.
$ asmcmd showclustermode
ASM cluster : (more...)
A few weeks ago we upgraded one of our production server, adding another CPU tray. This brought the number of CPU cores from 80 to 160, and took us from 2Tb of RAM to 4Tb (just in time for Oracle to announce the in-memory database in 22.214.171.124!).
However when I went to start things up, ASM wasn't starting up, giving me these errors:ORA-04031: unable to allocate 32 bytes of shared (more...)
If you use ASM on a regular basis, you may find that knowledge of the internals
can be very useful for advanced troubleshooting
and in general to acquire familiarity
with the technology. In particular this is even more relevant when using ASM capabilities for data redundancy/mirroring (i.e. when deploying disk groups with normal or high redundancy).
I have first started investigating this topic when deploying 10g RAC databases in 2005. From time to time (more...)
Last week I was lucky enough to be presenting at the UKOUG AIM SIG. There was a decent enough crowd in attendance and there were some really interesting talks and some really good speakers. In particularly I found Chris Lawless speaking on replication a particularly engaging speaker, and Dave Webster really held the audiences attention late in day.
I was giving a presentation on the new features available to you with 12c ASM. The presentation (more...)
I recently hit the problem covered in MOS note “ASM Instance Is Not Coming Up ORA-00064 (1,4468736,Kfchl Array) Kfchl Array (Doc ID 1328620.1)” mid-way through a Grid Infrastructure upgrade from 126.96.36.199 BP16 to 188.8.131.52 BP3 on Exadata. Specifically, it was the application of prerequisite patch 17783101 (required for downgrades) to node 3 that hit the problem. At this point nodes 1 and 2 had been successfully patched (more...)
Original Post can be viewed at Openfiler on Virtualbox and 12c Oracle Flex ASM
Last week Oracle released 12c database and Oracle blogosphere is bustling with lot of people posting details about new versions and setup. I too decided to take plunge and setup my own RAC cluster. I had (more...)
As you all may know, ASMLib is a recommended module for Oracle databases running on Linux platforms and it is an embedded module for UEK (Oracle Unbreakable Kernel) users. Oracle announced that (two years ago or so) they will no longer maintain ASMLib for Red Hat compatible kernel but this does not mean that they abandon the project, rather it is mainly related to the effort they need to put in maintaining the module for multiple kernel versions.
A while ago, Oracle added a new feature to ASMLib allowing ASM devices to choose between physical or logical block sizes in (more...)
Moving to Redhat Linux 5/Oracle Enterprise Linux 5, which does not support Raw filesytem.
Steps: (these steps can be performanced on 11gR2)
1.) Check the current location of ocr file:
[root@host1 bin]# ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 3
Total space (kbytes) : 262120
Used space (kbytes) : 3004
Available space (kbytes) : 259116
ID : 798462606
Device/File Name : /mnt/cludata/ocrfile
Device/File integrity check succeeded
Device/File not configured
Device/File not configured
Device/File not configured
Device/File not configured
Cluster registry integrity check succeeded
Logical corruption check succeeded
2.) Add a Mirror OCR (more...)
This is a quick post regarding the error on the subject. This is the second time it happens to me, so I thought I will write a bit about it.
I am refreshing one of my UAT environments (happens to be a Full Rack Exadata) using Oracle RMAN duplicate command. Then the following happens (on both occasions).
1.- Duplicate command fails (lack of space for restoring archivelogs, or any other error). This is can be fixed quite easy.
2.- following error while trying to open the database after restore and recover has finished:
SQL> alter database (more...)
Increase the PROCESSES parameter in the ASM parameter file
Processes = 25 + 15 * n, where n is the number of instances on the box using ASM for their storage.
NOTE : this formula is for a basic instance and does not accomodate for
* Multiple ARCH processes
* Multiple LGWR processes
Should the ORA-0020 occur even after implementing this formula ... add additional for any multiples of these background processes
Refer NOTE 265633.1 "ASM Technical Best Practices" for more information.