ACFS Snapshots

ACFS snapshot is a online read point-in-time copy of an Oracle ACFS file system. It can be used to recover a deteted file, revert to a prior version.  When the snapshot is created, a set of metadata including the directory structures, name of all files are created on the same volume.

+ASM1 > acfsutil registry -l
Device : /dev/asm/vol_share-356 : Mount Point : /share : Options : none : Nodes : all : Disk Group : DG_POC_ACFS : Volume : VOL_SHARE

Create ACFS snapshot image
+ASM1 > /sbin/acfsutil snap create snap_share001 /share
acfsutil snap create: Snapshot operation is complete.
/share/.ACFS/snaps/snap_share001 => is the snapshot file system

View  File System
+ASM1 > /sbin/acfsutil info fs /share
    ACFS Version: 11.2.0.2.0
    flags:        MountPoint,Available
    mount time:   Wed Oct 19 14:05:09 2011
    volumes:      1
    total size:   140660178944
    total free:   138043518976
    primary volume: /dev/asm/vol_share-356
        label:                 DBA Share FS
        flags:                 Primary,Available,ADVM
        on-disk version:       39.0
        allocation unit:       4096
        major, minor:          252, 182273
        size:                  140660178944
        free:                  138043518976
        ADVM diskgroup         DG_POC_ACFS
        ADVM resize increment: 268435456
        ADVM redundancy:       unprotected
        ADVM stripe columns:   4
        ADVM stripe width:     131072
    number of snapshots:  1
    snapshot space usage: 49152

Resize ACFS
+ASM1 > acfsutil size +3g /share
acfsutil size: new file system size: 140660178944 (134144MB)

View detail information on each file system
acfsutil info fs /share
acfsutil info fs /share -s (statistics)