9.8.3 Monitoring Sparse Disk Group Utilization
The V$ASM_DISK
and V$ASM_DISKGROUP
views contain information about the virtual size and utilization of the sparse ASM disk group. New views V$ASM_DISK_SPARSE
and V$ASM_DISKGROUP_SPARSE
contain information about the actual size and utilization of the sparse ASM disk group. V$ASM_DISK_SPARSE
also contains performance and usage metrics.
The following table describes the columns in V$ASM_DISK_SPARSE
:
Table 9-1 V$ASM_DISK_SPARSE Columns and Descriptions
Column | Description |
---|---|
|
The number of the disk group containing the disk. |
|
The number assigned to the disk within this disk group. |
|
The incarnation number for the disk. |
|
The total used physical and materialized capacity on the disk. |
|
The total physical capacity on the disk. |
|
The total number of I/O read requests on non-materialized regions of the disk. |
|
The total number of bytes read from non-materialized regions of the disk. |
|
The time taken by sparse read I/O operations. |
The following table describes the columns in V$ASM_DISKGROUP_SPARSE
:
Table 9-2 V$ASM_DISKGROUP_SPARSE Columns and Descriptions
Column | Description |
---|---|
|
The cluster-wide number assigned to the disk group. |
|
The total used physical and materialized capacity of the disk group. |
|
The total physical capacity of the disk group. |
The following example shows the used (allocated) space and the total space for disks in a specific disk group:
SQL> select DISK_NUMBER dsk_num, ALLOCATED_MAT_MB alloc, TOTAL_MAT_MB total from V$ASM_DISK_SPARSE where GROUP_NUMBER = 5; DSK_NUM ALLOC TOTAL ---------- ---------- ---------- 0 5536 57336 1 5424 57336 2 5532 57336 3 5424 57336 4 5424 57336
In the following example, sparse ASM grid disks were created with an actual size of
56 GB and a virtual size of 560 GB. When you query V$ASM_DISK
's
OS_MB
and TOTAL_MB
columns, you can see the
virtual size of 573440 MB (573440 MB / 1024 = 560 GB).
SQL> select os_mb, total_mb from v$asm_disk where group_number=4; OS_MB TOTAL_MB ---------- ---------- 573440 573440 573440 573440 573440 573440
Querying V$ASM_DISK_SPARSE
for TOTAL_MB
, you can see the actual size of the ASM grid disk available for use. Note that each ASM grid disk stores metadata information of approximately 2 MB per 16 GB of space allocated to the sparse ASM grid disk. For 56 GB allocated per grid disk in this example, 8 MB of space is reserved for sparse disk metadata (57336 MB + 8 MB = 57344 MB / 1024 = 56 GB).
SQL> select total_mb from v$asm_disk_sparse where group_number=4; TOTAL_MB --------- 57336 57336 57336
Parent topic: Managing Sparse Griddisks