Review this section to understand Oracle Database Appliance storage architecture and options and how to determine usable storage.
Use Oracle Automatic Storage Management (Oracle ASM) or Oracle Automatic Storage Management Cluster File System (Oracle ACFS) for database files storage.
Database file systems are used exclusively for storing database files, and they include a DATA file system for database data files and a RECO file system for storing archive files and backups. Oracle Database Appliance supports Oracle ACFS and Oracle ASM database file storage. You determine the type of database storage when you create the database. Beginning with Oracle Database Appliance 12.2, if you do not select a storage type, the default storage is Oracle ASM.
About Oracle ASM Database Storage
Use Oracle ASM with Oracle Database 12c release 2 (12.2.0.1) and 12c release 1 (12.1.0.2).
With Oracle ASM, database data files are stored in DATA diskgroup. Redo and archive files are in RECO diskgroup.
Reserved storage is the amount of Oracle Automatic Storage Management (Oracle ASM) storage required to maintain redundancy in the event of a disk failure. If you use the reserve storage capacity, then the system continues to run, and it is protected through Oracle ASM mirroring. However, in the event of a second disk failure, the system is then running in a non-protected and degraded mode. In this event, you must replace disks immediately.
About Oracle ACFS Database Storage
Oracle ACFS is supported with Oracle Database 12c release 2 (12.2.0.1), 12c release 1 (12.1.0.2), and Oracle Database 11g release 2 (11.2.0.4). Version 11.2.0.4 databases must use ACFS for storage.
With Oracle ACFS, an Oracle ACFS file system is created from DATA diskgroup for each database to store data files, and an Oracle ACFS file system is created from RECO diskgroup for REDO and fast recovery area for all databases.
Each database created under ACFS has it own mount points, /u02/app/oracle/oradata/dbid. When you delete a database, you should clean up the files.
lsdg command to display mounted disk groups and their information for Oracle Database Appliance.Parent topic: Storage on Oracle Database Appliance
Use Oracle Automatic Storage Management (Oracle ASM) or Oracle Automatic Storage Management Cluster File System (Oracle ACFS) for database files storage.
Database file systems are used exclusively for storing database files, and they include a DATA file system for database data files and a RECO file system for storing archive files and backups. Oracle Database Appliance supports Oracle Automatic Storage Management Cluster File System (Oracle ACFS) or Oracle Automatic Storage Management (Oracle ASM) database file storage. You determine the type of database storage when you create the database.
About Oracle ASM Database Storage
Use Oracle ASM with Oracle Database 12c release 2 (12.2.0.1) and 12c release 1 (12.1.0.2).
With Oracle ASM, database datafiles are stored in DATA diskgroup. Redo and archive files are in RECO diskgroup.
Reserved storage is the amount of Oracle Automatic Storage Management (Oracle ASM) storage required to maintain redundancy in the event of a disk failure. If you use the reserve storage capacity, then the system continues to run, and it is protected through Oracle ASM mirroring. However, in the event of a second disk failure, the system is then running in a non-protected and degraded mode. In this event, you must replace disks immediately.
About Oracle ACFS Database Storage
Oracle ACFS is supported with Oracle Database 12c release 2 (12.2.0.1), 12c release 1 (12.1.0.2), and Oracle Database 11g release 2 (11.2.0.4). Version 11.2.0.4 databases must use ACFS for storage.
With Oracle ACFS, an Oracle ACFS file system is created from DATA diskgroup for each database to store datafiles, and an Oracle ACFS file system is created from RECO diskgroup for redo and fast recovery area for all databases.
Each database created under ACFS has it own mount points, /u02/app/oracle/oradata/dbid. When you delete a database, you should clean up the files.
Storage Configuration Options
When Oracle Database Appliance is deployed, you can configure how the storage capacity is shared between DATA diskgroup and RECO diskgroup. You can choose anywhere from 10% to 90% for DATA and the remainder for RECO. The amount of usable storage is determined by the percentage configured for DATA. You can run the command lsdg to determine the usable storage on the DATA disk group.
Parent topic: About Oracle Database File Storage
Review Oracle ASM Cluster file system (ACFS) mount points for Oracle Database Appliance.
If you select Oracle Automatic Storage Management (Oracle ASM) for database storage when you create a database, then an Oracle ASM Cluster file system (ACFS) is not created. All files are in an Oracle ASM diskgroup.
If you select Oracle ACFS for database storage, then each database has its own Oracle ACFS mount point:
DATA diskgroup: /u02/app/oracleuser/oradata/db_name
RECO diskgroup: /u03/app/oracleuser.
With Oracle ACFS, the following are created:
A 100G ACFS is created from +DATA diskgroup for each database. This Oracle ACFS automatically extends the space on demand.
A common Oracle ACFS with 25% of +RECO diskgroup is created with auto extension on. This file system is used for fast recovery area and redo logs for all databases.
Table B-1 Oracle ACFS Mount Points and Related Oracle ASM Disk Groups and Volume Information
| File System | Oracle ASM Disk Group | Oracle ASM Dynamic Volume | Mount Point |
|---|---|---|---|
|
DATA |
+DATA |
For example: |
For example: |
|
RECO |
+RECO |
|
This mount point is shared by all databases for For For redo logs, the path is: |
Example B-1 Oracle ACFS Storage Space
When the Oracle ACFS file systems are created, they do not initially consume all of the storage in the appliance. Space is preserved for additional repositories, or in some cases, database files stored directly in Oracle ASM. You can check for available storage space in your file systems by running the operating system command df -k as shown in the following example.
# df -k Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/VolGroupSys-LogVolRoot 30963708 14203568 15187276 49% / tmpfs 65952292 647800 65304492 1% /dev/shm /dev/sda1 495844 43872 426372 10% /boot /dev/mapper/VolGroupSys-LogVolOpt 61927420 18594420 40187272 32% /opt /dev/mapper/VolGroupSys-LogVolU01 103212320 49621560 48347880 51% /u01 /dev/asm/reco-62 76546048 1469676 75076372 2% /u03/app/oracle /dev/asm/datrdb2-268 104857600 3872368 100985232 4% /u02/app/oracle/oradata/rdb2 /dev/asm/datndb11-268 104857600 247160 104610440 1% /u02/app/oracle/oradata/ndb11 /dev/asm/datndb12-268 104857600 247160 104610440 1% /u02/app/oracle/oradata/ndb12
Parent topic: About Oracle Database File Storage
Use the Oracle Automatic Storage Management lsdg command to display mounted disk groups and their information for Oracle Database Appliance.
grid user.lsdg command.Example B-2 Determining Storage on the DATA Disk Group
ASMCMD [+] > lsdg data
State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB
MOUNTED NORMAL N 512 4096 4194304 12288 8835 1117 3859
(continued)
Offline_disks Voting_files Name
0 N DATA
Parent topic: About Oracle Database File Storage
Review the table for the approximate amount of usable space for Oracle Database Appliance X7-2S and X7-2M.
Oracle Database Appliance X7-2S and X7-2M use 6.4TB NVMe. The usable data capacity varies because it is derived by converting disk hardware terabytes (based on 1 kilobyte equals 1,000 bytes) into software storage terabytes (based on 1 kilobyte equals 1,024 bytes) and splitting the usable capacity into Oracle Automatic Storage Management (Oracle ASM) disk groups.
The estimated usable space is calculated based on the number of drives, where 90% is allocated to data.
Table B-2 Usable Disk Capacity on Oracle Database Appliance X7-2S and X7-2M
| Number of Drives (90% allocated to data) | Normal Redundancy | High Redundancy |
|---|---|---|
|
X7-2S 2 drives (12.8TB raw storage) |
|
Not applicable |
|
X7-2M 2 drives (12.8TB raw storage) |
|
Not applicable |
|
X7-2M 5 drives (32TB raw storage) |
|
|
|
X7-2M 8 drives (51.2TB raw storage) |
|
|
The Reservation value represents the amount of storage required to maintain full redundancy in case of disk failure.
Parent topic: Storage on Oracle Database Appliance
Review the table for the approximate amount of usable space for high performance or high capacity on Oracle Database Appliance X7-2-HA.
Usable Space for High Performance
Oracle Database Appliance X7-2-HA use 3.2 TB solid state drives (SSDs). The usable data capacity varies because it is derived by converting disk hardware terabytes (based on 1 kilobyte equals 1,000 bytes) into software storage terabytes (based on 1 kilobyte equals 1,024 bytes) and splitting the usable capacity into Oracle Automatic Storage Management (Oracle ASM) disk groups.
The estimated usable space is calculated based on the number of drives, where 90% is allocated to data.
Table B-3 Usable Disk Capacity for High Performance on Oracle Database Appliance X7-2-HA
| Number of Drives (90% allocated to data) | Normal Redundancy | High Redundancy |
|---|---|---|
|
5 drives (16 TB raw storage) |
|
|
|
10 drives (32 TB raw storage) |
|
|
|
15 drives (48 TB raw storage) |
|
|
|
20 drives (64 TB raw storage) |
|
|
|
40 drives (128 TB raw storage) |
|
|
The Reservation value represents the amount of storage required to maintain full redundancy in case of disk failure.
The REDO disk group uses 800 GB raw Solid-State Drives or 0.8 TB total usable space. The REDO disk group uses high redundancy that provides approximately 0.3 TB usable space for database redo logs.
Note:
For an Oracle Database Appliance virtualized platform:
Nn-CDB databases, the REDO disk group has 50% free disk space.
CDB databases, an Oracle ASM Cluster file system (ACFS) mount point is created per CDB database, based on the template log file size. If this is a Single Instance (SI) database, then multiply by 3. If the database is an Oracle RAC database, then multiply by 4.
Usable Space for High Capacity
The usable space for high capacity assumes that 90% is allocated to data and that you use external backup.
Table B-4 Usable Disk Capacity for High Capacity on Oracle Database Appliance X7-2-HA
| Number of Drives (90% allocated to data) | Normal Redundancy | High Redundancy |
|---|---|---|
|
15 drives (150 TB raw storage) |
|
|
|
30 drives (300 TB raw storage) |
|
|
Parent topic: Storage on Oracle Database Appliance
When Oracle ASM calculates usable Free Space, it determines the amount of space to reserve in the case of a disk failure.
For Oracle Database Appliance with 2 or 4 NVMe drives, this reserved space is not required. When you query Oracle ASM or Oracle Database Appliance commands to view the amount of storage available, the usable_File_MB value may report a negative number.
Table B-5 Oracle ASM Calculations
| Number of Drives | Redundancy | Total_MB | Free_MB | Req_mir_free_MB | Usable_file_MB | Name |
|---|---|---|---|---|---|---|
|
2 |
NORMAL |
4894016 |
4893372 |
0 |
1220644 |
RECO/ |
|
4 |
NORMAL |
1231176 |
1230996 |
610468 |
305150 |
RECO/ |
Note:
Note: 1TB = MB divided by 10242How Oracle ASM and Oracle Database Appliance Define Capacity
The following table describes how capacity terms are defined by Oracle ASM and Oracle Database Appliance.
Table B-6 Definition of Terminology
| Term | Oracle ASM Definition | Oracle Database Appliance Definition |
|---|---|---|
|
|
Size of the disk group in MB |
Total usable storage. For example, for 2 NVMe drives, total usable storage is 5.8TB. |
|
|
Free space in the disk group in MB, without regard to redundancy. |
Total usable storage after formatting to Oracle ASM disk groups. For example, for 2 NVMe drives, total usable storage is 5.8TB. |
|
|
Amount of space that must be available in the disk group to restore full redundancy after the worst failure that can be tolerated by the disk group. |
Total usable storage after formatting to Oracle ASM disk groups. For example, for 2 NVMe drives, total usable storage is 5.8TB. |
|
|
Amount of free space, adjusted for mirroring, that is available for new files. |
Total usable space taking into consideration the mirroring level. Oracle ASM also calculates the amount of space required. |
Parent topic: Storage on Oracle Database Appliance