Oracle Grid Infrastructure 19c – Oracle ASM Filter Driver (ASMFD)

Following a discussion on the options on how to reclaim space (TRIM/Unmap) on Oracle database using flash storage I though this would make a good topic for a new Blog post.

If your Oracle database is using a modern file system it’s pretty straight forward, use the ‘discard’ option. However for the majority of us using Oracle Automatic Storage Management (ASM) we need to work a bit harder.

I have previously Blogged on how to set-up Oracle ASMFD at the command line, this time I will share how to do this with Oracle Grid Infrastructure.

Oracle Grid Infrastructure 19c Installer

Step 1 – Select Configuration Option
Step 2 – Create ASM Disk Group

As I plan to use the Oracle ASM Filter Driver I have selected ‘Configure Oracle ASM Filter Driver’, also as I have access to an All-Flash Pure Storage FlashArray I am able to set the Redundancy to ‘External’. The Pure Storage FlashArray will provide RAID data protection, if your storage platform is not able to provide RAID protection you will need to select ‘Normal’ 2-way or ‘High’ 3-way mirroring.

Step 3 – Specify ASM Password
Step 4 – Specify Management Options
Step 5 – Privileged Operating System Groups
Step 6 – Specify Installation Location
Step 7 – Root script execution configuration
Step 9 – Summary
Step 10 – Install Product


We can now use ASMCMD to check that the ASM Filter Driver (ASMFD) is configured as expected.

afd_state – Returns the state of Oracle ASM Filter Driver.

[oracle@z-oracle ~]$ asmcmd afd_state
ASMCMD-9526: The AFD state is 'LOADED' and filtering is 'ENABLED' on host ''

afd_lsdsk – Lists Oracle ASM Filter Driver disks.

[oracle@z-oracle ~]$ asmcmd afd_lsdsk
Label                     Filtering   Path
DATA1                       ENABLED   /dev/oracleasm/dg_oradata1
DATA2                       ENABLED   /dev/oracleasm/dg_oradata2
DATA3                       ENABLED   /dev/oracleasm/dg_oradata3
DATA4                       ENABLED   /dev/oracleasm/dg_oradata4

afd_lslbl – Lists the disks that contain Oracle ASM Filter Driver labels.

[oracle@z-oracle ~]$ asmcmd afd_lslbl /dev/oracleasm/
Label                     Duplicate  Path ======================================================================
DATA1                                 /dev/oracleasm/dg_oradata1
DATA2                                 /dev/oracleasm/dg_oradata2
DATA3                                 /dev/oracleasm/dg_oradata3
DATA4                                 /dev/oracleasm/dg_oradata4

lsdsk – Lists Oracle ASM disks.

[oracle@z-oracle ~]$ asmcmd lsdsk -t -G DATA
Create_Date  Mount_Date  Repair_Timer  Path
12-OCT-19    12-OCT-19   0             AFD:DATA1
12-OCT-19    12-OCT-19   0             AFD:DATA2
12-OCT-19    12-OCT-19   0             AFD:DATA3
12-OCT-19    12-OCT-19   0             AFD:DATA4

lsattr – Lists the attributes of a disk group.

[oracle@z-oracle ~]$ asmcmd lsattr -lm -G DATA 
Group_Name  Name                        Value         RO  Sys  
DATA        access_control.enabled      FALSE         N   Y    
DATA        access_control.umask        066           N   Y    
DATA        appliance._partnering_type  GENERIC       Y   Y    
DATA        ate_conversion_done         true          Y   Y    
DATA        au_size                     4194304       Y   Y    
DATA        cell.smart_scan_capable     FALSE         N   N    
DATA        cell.sparse_dg              allnonsparse  N   N    
DATA        compatible.advm       N   Y    
DATA        compatible.asm        N   Y    
DATA        compatible.rdbms      N   Y    
DATA        content.check               FALSE         N   Y    
DATA        content.type                data          N   Y    
DATA        content_hardcheck.enabled   FALSE         N   Y    
DATA        disk_repair_time            12.0h         N   Y    
DATA        failgroup_repair_time       24.0h         N   Y    
DATA        idp.boundary                auto          N   Y    
DATA        idp.type                    dynamic       N   Y    
DATA        logical_sector_size         512           N   Y    
DATA        phys_meta_replicated        true          Y   Y    
DATA        preferred_read.enabled      FALSE         N   Y    
DATA        scrub_async_limit           1             N   Y    
DATA        scrub_metadata.enabled      TRUE          N   Y    
DATA        sector_size                 512           N   Y    
DATA        thin_provisioned            FALSE         N   Y    
DATA        vam_migration_done          false         Y   Y 

As we can see from above the ASMFD thin_provisioned default value is FALSE

In my next Blog post I explore the impact of the ASMFD thin_provisioned setting on space management with flash storage.


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