Asm diskgroup really full?

Question

Hi gurus,
after install RAC (11.2.0.3 two nodes) on linux, a warning appears shown a diskgroup almost full:
SQL>  select group_number,  name, block_size, state, total_mb, free_mb, hot_used_mb from V$ASM_DISKGROUP WHERE NAME='VOL';
GROUP_NUMBER NAME                           BLOCK_SIZE STATE         TOTAL_MB      FREE_MB HOT_USED_MB
           4 VOL                          4096 MOUNTED          23838       284           0correctly, It's looks like almost full.
It is a new RAC database, if i check any file at asmcmd:
asmcmd> cd VOL
asmcmd> ls
asmcmd>no files appear, so i go to asmca and check:
ASM CLUSTER FILE SYSTEM
ACTIVE MOUNT POINT | STATE | ALL_MOUNT_POINTS | VOLUME DEVICE    | SIZE (GB) | VOLUME | DISK_GROUP | USED (%)
/backup                 MOUNTED   /backup           /dev/asm/vol-24   22.91      VOL VOL       4.19it's only 4.19% in use
what is happening? at filesystem is no files and have enough space, but asm shows that it is almost full

Answer 1

ASM and ACFS are related (an ACFS volume is part of an ASM diskgroup), but not the same
you have ASM diskgroup with 23 GB storage
you created an ACFS volume on it with ~23 GB size
from ASM point of view, the diskgroup is almost full, because of the ACFS volume
from ACFS point of view, its empty, because you didnt put anything yet on that volume
its similar as LVM
you create a volume group (ASM diskgroup in this analogy) with 23 GB size
then you create a volume (ACFS volume in this analogy) with nearly 23 GB size
volume group is almost "full", while volume is empty