1. X11 Deployment and User’s Guide
  2. Oracle Database Appliance Storage Defaults

B Oracle Database Appliance Storage Defaults

Review this section to understand Oracle Database Appliance storage architecture and options and how to determine usable storage.

About Database File 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 separate file systems for data files and archive files or backups. You determine the type of database storage when you create the database.

About Oracle ASM Database Storage

With Oracle ASM, database datafiles are stored in DATA disk group. On X8-2, X7-2S, X7-2M, and X6-2 S/M/L systems, which do not have REDO disk group, redo and archive files are stored in RECO disk group. X7-2-HA and other older High-Availability systems have dedicated disks for REDO disk group; redo logs are stored in the REDO disk group.

Reserved storage is the amount of Oracle Automatic Storage Management (Oracle ASM) storage required to restore 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 disk failure, the system is then running in a non-protected and degraded mode. In this event, you must replace disks immediately. If there is no reserved space available, then rebalance cannot restore redundancy after a disk failure.

If you specify mirroring for a file, then Oracle ASM automatically stores redundant copies of the file extents in separate failure groups. Failure groups apply to normal, high, and flex redundancy disk groups. You can define the failure groups for each disk group when you create or alter the disk group.

See Also:

Oracle Automatic Storage Management Administrator’s Guide in the Oracle Database documentation library for information about Oracle ASM Mirroring and Disk Group Redundancy.

About Oracle ACFS Database Storage

With Oracle ACFS, an Oracle ACFS file system is created from DATA disk group for each database to store datafiles, and an Oracle ACFS file system is created from RECO disk group 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 disk group and RECO disk group. 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 asmcmd lsdg to determine the usable storage on the DATA disk group. You can also run the command odacli list-dbstorages command to determine the storage available.

Parent topic: Oracle Database Appliance Storage Defaults

Oracle ACFS Mount Points and Storage Space

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 disk group.

If you select Oracle ACFS for database storage, then each database has its own Oracle ACFS mount point:

  • DATA disk group: /u02/app/oracleuser/oradata/db_name

  • RECO disk group: /u03/app/oracleuser.

  • REDO disk group: /u04/app/oracleuser/redo/db_name

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.

  • For Oracle Database Appliance single-node and High-Availability High Performance systems, the REDO volume is created on the RECO disk group. For Oracle Database Appliance High-Availability High Capacity system, the REDO volume is created on FLASH disk group. The REDO volume stores redo logs.

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

/dev/asm/datdbname-nnn

For example: /dev/asm/datodacn-123

/u02/app/oracleuser/oradata/dbname

For example: /u02/app/example/oradata/odacn

RECO

+RECO

/dev/asm/reco-nn

/u03/app/oracleuser

This mount point is shared by all databases for fast_recovery_area and redo logs.

For fast_recovery_area, the path is: /u03/app/oracleuser/fast_recovery_area/db_name
REDO +RECO/+FLASH depending on environment type (High Capacity or High Performance) /dev/asm/rdo/dbName-nnn /u04/app/oracleuser/redo/db_name

For example:

/u04/app/oracle/redo/mydb

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: Oracle Database Appliance Storage Defaults

Displaying Mounted Disk Details

Use the Oracle Automatic Storage Management lsdg command to display mounted disk groups and their information for Oracle Database Appliance.

To display information about a specific disk group, specify the disk group in the command.
  1. Log in as a grid user.
  2. Run the Oracle Automatic Storage Management 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: Oracle Database Appliance Storage Defaults

Usable Space on Oracle Database Appliance X11-S and X11-L

Review the table for the approximate amount of usable space for Oracle Database Appliance X11-S and X11-L.

Oracle Database Appliance X11-S and X11-L use 6.8TB NVMe. The storage capacity is the aggregate for DATA and RECO disk groups. The raw storage capacity in the table is based on disk hardware terabytes (based on 1 kilobyte equals 1000 bytes). Approximate usable storage capacity is shown in software storage terabytes (based on 1 kilobyte equals 1024 bytes). Approximate usable storage also accounts for 15% reserved space required to restore full redundancy in case of disk failure (not applicable to the two-drive configuration). The high redundancy values in the table describe the space needed to recover from one failure only.

Note:

The usable storage space described in this topic are approximate values, and may vary as per your deployment.

Table B-2 Usable Disk Capacity on Oracle Database Appliance X11-S and X11-L

Number of Drives Raw Storage Usable Storage with Normal Redundancy (Double Mirroring) Usable Storage with High Redundancy (Triple Mirroring)

X11-S/X11-L (2 drives)

 13.6 TB

6.2 TB

 Not Applicable

X11-L (4 drives)

 27.2 TB 10.5 TB 7.0 TB

X11-L (6 drives)

 40.8 TB 15.8 TB 10.5 TB

X11-L (8 drives)

54.4 TB 21.0 TB 14.0 TB

Parent topic: Oracle Database Appliance Storage Defaults

Usable Space on Oracle Database Appliance X11-HA

Review the table for the approximate amount of usable space for high performance and high capacity storage on Oracle Database Appliance X11-HA.

Usable Space for High Performance

Note:

The usable storage space described in this topic are approximate values, and may vary as per your deployment.

Oracle Database Appliance X11-HA with high performance configuration uses 7.68TB solid state drives (SSDs). The storage capacity is the aggregate for DATA and RECO disk groups. The raw storage capacity in the table is based on disk hardware terabytes (based on 1 kilobyte equals 1000 bytes). Approximate usable storage capacity is shown in software storage terabytes (based on 1 kilobyte equals 1024 bytes). Approximate usable storage also accounts for 15% reserved space required to restore full redundancy in case of disk failure. The high redundancy values in the table describe the space needed to recover from one failure only.

Table B-3 Usable Disk Capacity for High Performance on Oracle Database Appliance X11-HA

Number of Drives Raw Storage Usable Storage with Normal Redundancy (Double Mirroring) Usable Storage with High Redundancy (Triple Mirroring)

6 SSD drives

 46 TB 17.8 TB 11.9 TB

12 SSD drives

92 TB

 35.6 TB 23.7 TB

18 SSD drives

 138 TB 53.4 TB 35.6 TB

24 SSD drives

184 TB 71.2 TB 47.5 TB

48 SSD drives

 369 TB 142.5 TB 95.0 TB

Usable Space for High Capacity

Oracle Database Appliance X11-HA with high capacity configuration uses 7.68TB solid state drives (SSDs) and 22TB hard disk drives (HDDs). SSD storage capacity is allocated to the FLASH disk group. HDD storage capacity is the aggregate for DATA and RECO disk groups. The raw storage capacity in the table is based on disk hardware terabytes (based on 1 kilobyte equals 1000 bytes). Approximate usable storage capacity is shown in software storage terabytes (based on 1 kilobyte equals 1024 bytes). Approximate usable storage also accounts for 15% reserved space required to restore full redundancy in case of disk failure. The high redundancy values in the table describe the space needed to recover from one failure only.

Note:

The usable storage space described in this topic are approximate values, and may vary as per your deployment.

Table B-4 Usable Disk Capacity for High Capacity on Oracle Database Appliance X11-HA

Number of Drives Raw Storage Usable Storage with Normal Redundancy (Double Mirroring) Usable Storage with High Redundancy (Triple Mirroring)
6 SSD drives and 18 HDD drives

SSDs: 46 TB

HDDs: 396 TB

SSDs: 17.8 TB

HDDs: 153.1 TB

SSDs: 11.9 TB

HDDs: 102 TB
12 SSD drives and 36 HDD drives

SSDs: 92 TB

HDDs: 792 TB

SSDs: 35.6 TB

HDDs: 306.1 TB

SSDs: 23.7 TB

HDDs: 204.1 TB

Parent topic: Oracle Database Appliance Storage Defaults

Usable Free Space with Oracle ASM

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 10242

How 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

Total_MB

Size of the disk group in MB

Total usable storage. For example, for 2 NVMe drives, total usable storage is 5.8TB.

Free_MB

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.

Req_mir_free_MB

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.

Amount of space that must be available in the disk group to restore full redundancy after the most severe failure that can be tolerated by the disk group. This is the REQUIRED_MIRROR_FREE_MB column from the V$ASM_DISKGROUP view.

Usable_file_MB

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: Oracle Database Appliance Storage Defaults