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In this reference architecture, we use the following best practices to deploy and configure RHEL 7.4 as the guest operating system in the VM running the Oracle standalone database:
Important best practices include:
KERNEL=="sd[a-z]*[1-9]", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d /dev/$parent", RESULT=="3600601600f004300accaed5bd9741db5", SYMLINK+="oracleasm/disks/ora-redo1", OWNER="grid", GROUP="asmadmin", MODE="0660"
Note: For this reference architecture, we tested the standalone Oracle Database 18c by performing an in-place upgrade of the deployed 12cR2 database. For an overview of the upgrade process, see Upgrading Oracle Database 12cR2 to 18cR1.
As described in Unity 650F storage design, we mapped all Oracle related LUNs that are presented to the ESXi host from the Unity 650F storage array directly as raw devices to the database VM through RDM. In compliance with the UDEV rules, we assigned the ownership of the raw devices to the grid user who is the owner of the Oracle GI and Oracle Automatic Storage Management (ASM). The device link for these Oracle related raw devices is /dev/oracleasm/disks/ora-XXX. For example, /dev/oracleasm/disks/ora-redo1 is the device link for REDO1 LUN/raw device.
The following table shows the Oracle disk groups that are created based on these LUNs/raw devices. Except for the OCR disk group that uses the normal redundancy (with triple mirroring), all other disk groups use the external redundancy setting. The coarse striping setting is also used for DATA, FRA, and OCR disk groups, and the fine-grain striping setting is used for REDO1, REDO2, and TEMP disk groups.
Table 5. ASM disk group design
ASM disk group | Purpose | Redundancy | ASM striping | ASM disk group size (GB) | LUN | LUN size (GB) |
DATA | Data files, control files, undo tablespace | External redundancy | Coarse | 2,000 | DATA00 | 500 |
DATA01 | 500 | |||||
DATA02 | 500 | |||||
DATA03 | 500 | |||||
FRA | Archive log files | External redundancy | Coarse | 200 | FRA0 | 100 |
FRA1 | 100 | |||||
REDO1 | Online redo logs | External redundancy
| Fine-grain | 50 | REDO0 | 25 |
REDO1 | 25 | |||||
REDO2
| Online redo logs | External redundancy
| Fine-grain
| 50 | REDO2 | 25 |
REDO3 | 25 | |||||
TEMP
| Temp files | External redundancy
| Fine-grain
| 500 | TEMP
| 500
|
OCR | OCR, voting disk, GIMR | Normal redundancy | Coarse
| 50 | OCR0 | 50 |
OCR1 | 50 | |||||
OCR3 | 50 |
Oracle ASM has a feature to move the data to higher performance tracks of the spinning disks in the compact phase at the end of ASM disk rebalancing. This feature has no benefit for Dell EMC Unity storage when the physical storage is virtualized and the flash devices are used. You can disable the rebalancing feature by running the alter diskgroup command for all the disk groups. The following example shows the command for the DATA disk group:
SQL> alter diskgroup DATA set attribute '_rebalance_compact' = 'FALSE';
For more information about the ASM disk group guidelines, see Dell Unity: Oracle Database Best Practices. For more information about ASM compact rebalancing, see Oracle Support note 1902001.1.