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Kathrine Selvage

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Aug 2, 2024, 7:48:08 PM8/2/24

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Another execution of fsck with Auto-fix option, helped. All problematic inodes reported above were auto-corrected. With same set of permissions (as reported earlier) for crsctl.bin and crsctl, Oracle HAS started without issues.

This short article will be about Oracle AFD driver introduced with Oracle 12c. As always I will write only about specific points which are not described in other sources. If you want to get more information about AFD driver refer to Oracle documentation, there are also many blogs describing it.

Oracle AFD stands for Oracle ASM Filter Driver, it is intended to replace ASMLIB driver for Linux. Oracle will develop and extend AFD driver. From main benefits it have filtering possibility, which filters all IO requests to manged devices, only oracle utilities can write to it if filtering is enabled. Oracle says that it also supports Storage thin provisioning which is now included with most of the modern storage producers. In the future releases it should perform also some logical checking during IO.

Managing utilities and libraries for Oracle AFD are part of oracle software binaries and installed with oracle installation, like ACFS utilities and drivers, actually it is same concept. There is positive and negative sides of it. Positive is that we do not need to separately download and install required drivers, negative side is that we need to configure ASM candidate disks before installation but there is no configuration utility beforehand.

During installation we should provide ASM disks to configure ASM in case of SIHA installation and additionally to locate Voting files and OCR file in case of Clusterware installation. If we want to use AFD driver from very beginnig, it is clear that we should first use Oracle AFD utilities to label some disks for installation, but these utilities will be available after installation! The only way is to do software-only installation first then load AFD module to Linux kernel and label disks, after that configure HAS or CRS depending on installation mode.

There is one important point, when we do software-only installation oracle copies binaries and relinks them. But it do not create wrapper scripts around this binaries. For example in bin directory of the GI home there is crsctl wrapper script and crsctl.bin binary executable. Now, after software-only installation there will be only crsctl.bin binary and no wrapper script crsctl and for some incomprehensible reason AFD configuration utilities uses wrapper scripts and not directly binaries, it is true for direct utilities like afdroot and when you call them over asmcmd! That is why just doing software-only installation is not enough. Related wrapper scripts are created after home configuration! In case of SIHA installation it is not a problem, because we do not have OCR or Voting files, we can execute roothas.pl to configure GI home and start HAS stack, then we will label disks and configure ASM with asmca.

It is not the way that I use personally but also the option. After installation we will require two wrapper scripts crsctl and clsecho. Just copy them from any existing 12c GI installation, it can be aslo SIHA installtion. After copying these wrapper scripts to the GI home, check the variables inside them for home locations, if required edit them to point to current home. Now you can use asmcmd for AFD configuration and disk labeling.

It is the way I always prefer to use. I usually do installation and patching process only ones, then I create tgz package from prepared home and use it for all other installations. It is much faster and simpler process, especially when well scripted ? After you will copy home from existing GI installation, it can be also SIHA GI home, you will already have crsctl and clsecho wrapper scripts inside. You must only check the path variables in the scripts header to point to current home.

Use asmcmd to configure AFD driver, this step will load oracleafd module into the kernel and create related files. It should create /etc/afd.conf file and /etc/init.d/afd script to load AFD module on startup. Check existens of these files manually, because there is BUG when these files not created automatically.

I personally will suggest to use Logical Sector size which is usually 512 bytes. Last years there is new disks on the market with 4k sector size. But Oracle software is not 100% ready for 4k Sector size disks by my opinion, there is many related bugs. Also, it is possible that you will have disks with different Physical sector sizes on same machine, in this case you must use Logical sector size, because you can not have disks with different sector sizes in one Disk Group.