What is the Oracle ASM Cluster Filesystem (ACFS) and How to Create ACFS

Mehmet Salih Deveci July 29, 2019 3 Comments

I will explain What is the Oracle ASM Cluster Filesystem (ACFS) and How to Create ACSF.

Oracle ACFS ( ASM Cluster Filesystem )

Oracle Automatic Storage Management Cluster File System (Oracle ACFS) is introduced in Oracle 11g Release 2 version. If you don’t know what is the Automatic Storage Management ( ASM ), you should read following article before this.

Oracle Automatic Storage Management ( ASM ) -1 Add Disk and Drop Disk Operations in Oracle ASM

ACFS ( ASM Cluster Filesystem )

ACFS is a Cluster file system like Local file system that you can store Application files, including executables, database trace files, database alert logs, application reports, BFILEs, configuration files, video, audio, text, images, engineering drawings, and other general-purpose application file data.

Application can use ASM Disks and storage via ACFS as if it is local disk as shown above. ACFS behaves as shared disk between Oracle RAC nodes, so it is very advantageous.

Create ACFS File System

ACFS can be created via asmcmd,asmca and Enterprise manager tool.

You can create and mount ACFS disk via asmcmd like following.

Step-1: Login asmcmd tool and create ACFS volume like following.

[grid@MehmetSalih01 .ssh]$ asmcmd

ASMCMD> volcreate -G RECO -s 10000G ACFS_VOL1
ASMCMD> 
ASMCMD>

Step 2: List and check it if it is created or not.

ASMCMD> volinfo --all
Diskgroup Name: RECO

Volume Name: ACFS_VOL1
Volume Device: /dev/asm/acfs_vol1-375
State: ENABLED
Size (MB): 10240000
Resize Unit (MB): 512
Redundancy: HIGH
Stripe Columns: 8
Stripe Width (K): 1024
Usage: 
Mountpath: 

ASMCMD> exit
[grid@MehmetSalih01 .ssh]$

Step -3: Create a file system on the ACFS volume.

[grid@MehmetSalih01 .ssh]$ 
[grid@MehmetSalih01 .ssh]$ 
[grid@MehmetSalih01 .ssh]$ /sbin/mkfs -t acfs /dev/asm/acfs_vol1-375
mkfs.acfs: version = 12.2.0.1.0
mkfs.acfs: on-disk version = 46.0
mkfs.acfs: volume = /dev/asm/acfs_vol1-375
mkfs.acfs: volume size = 10737418240000 ( 9.77 TB )
mkfs.acfs: Format complete.
[grid@MehmetSalih01 .ssh]$ 
[grid@MehmetSalih01 .ssh]$ 
[grid@MehmetSalih01 .ssh]$ 
[grid@MehmetSalih01 .ssh]$ exit
logout
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]#

Step -4: Login with root user, set ASM profile, Add and register this filesystem to CRS.

[root@MehmetSalih01 ~]# . oraenv
ORACLE_SID = [root] ? +ASM1
The Oracle base has been set to /u01/app/grid
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]# mkdir /backup
[root@MehmetSalih01 ~]# $ORACLE_HOME/bin/srvctl add filesystem -d /dev/asm/acfs_vol1-375 -m /backup -u grid -fstype ACFS -autostart ALWAYS
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]#

Step -5: Check mount point before start and mount this file system. ACFS does not exist now.

[root@MehmetSalih01 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VGExaDb-LVDbSys1
                       30G   22G  4.7G  84% /
tmpfs                 755G  617M  754G   1% /dev/shm
/dev/sda1             488M   28M  425M   7% /boot
/dev/mapper/VGExaDb-LVDbOra1
                       99G   74G   21G  79% /u01
/dev/sda2             254M   24M  231M  10% /boot/efi
[root@MehmetSalih01 ~]#

ASM file system ( ACFS )

Step 6: Start filesystem and Mount it like following.

[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]# $ORACLE_HOME/bin/srvctl start filesystem -d /dev/asm/acfs_vol1-375
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]# 
[root@MehmetSalih01 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VGExaDb-LVDbSys1
                       30G   22G  4.7G  84% /
tmpfs                 755G  617M  754G   1% /dev/shm
/dev/sda1             488M   28M  425M   7% /boot
/dev/mapper/VGExaDb-LVDbOra1
                       99G   74G   21G  79% /u01
/dev/sda2             254M   24M  231M  10% /boot/efi
/dev/asm/acfs_vol1-375
                      9.8T   22G  9.8T   1% /backup
[root@MehmetSalih01 ~]#

You can create ACFS volume and ACFS disk via asmca like following.

Run asmca tool and go to create new ACFS volume like following.