How To Resize Oracle ACFS Volume

There may be many reasons as to why Oracle ACFS volume would need to be resized.

Current Filesystem for ACFS is 299G.

Filesystem             Size  Used Avail Use% Mounted on
/dev/asm/acfs_vol-177  299G  2.6G  248G   2% /ggdata02

Free_MB is 872 which causes paging due to insufficient FREE space from ASM Disk Group ACFS_DATA.

$ asmcmd lsdg -g ACFS_DATA
Inst_ID  State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name
      1  MOUNTED  EXTERN  N         512   4096  4194304    307184      872                0             872              0             N  ACFS_DATA/
      2  MOUNTED  EXTERN  N         512   4096  4194304    307184      874                0             872              0             N  ACFS_DATA/

Option 1 is to exclude monitoring for ASM Disk Group ACFS_DATA to fully utilize allocated storage.
Option 2 is to resize ACFS to have sufficient free space for ASM Disk Group ACFS_DATA to prevent paging.

In this case, it was decided to resize ACFS volume to a smaller size to prevent paging for free space alert for ASM Disk Group.

Review attributes for ASM Disk Group ACFS_DATA:

$ asmcmd lsattr -l -G ACFS_DATA
Name                     Value
access_control.enabled   FALSE
access_control.umask     066
au_size                  4194304
cell.smart_scan_capable  FALSE
compatible.advm          12.1.0.0.0
compatible.asm           12.1.0.0.0
compatible.rdbms         12.1.0.0.0
content.check            FALSE
content.type             data
disk_repair_time         3.6h
failgroup_repair_time    24.0h
idp.boundary             auto
idp.type                 dynamic
phys_meta_replicated     true
sector_size              512
thin_provisioned         FALSE

Resize /ggdata02 to 250G:

$ acfsutil size 250G /ggdata02
acfsutil size: new file system size: 268435456000 (256000MB)

Review results:

$ asmcmd lsdg -g ACFS_DATA
Inst_ID  State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name
      1  MOUNTED  EXTERN  N         512   4096  4194304    307184    51044                0           51044              0             N  ACFS_DATA/
      2  MOUNTED  EXTERN  N         512   4096  4194304    307184    51044                0           51044              0             N  ACFS_DATA/
$ df -h /ggdata02
Filesystem             Size  Used Avail Use% Mounted on
/dev/asm/acfs_vol-177  250G  2.6G  248G   2% /ggdata02
$ asmcmd volinfo --all
Diskgroup Name: ACFS_DATA
	 Volume Name: ACFS_VOL
	 Volume Device: /dev/asm/acfs_vol-177
	 State: ENABLED
	 Size (MB): 256000
	 Resize Unit (MB): 512
	 Redundancy: UNPROT
	 Stripe Columns: 8
	 Stripe Width (K): 1024
	 Usage: ACFS
	 Mountpath: /ggdata02

In conclusion, acfsutil can be used to resize ACFS volume either by increasing or decreasing size.