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A local file system is preferred to store Oracle software and diagnostic logs. Datafiles can be stored in local file systems, but it is recommended to use Oracle ASM on block devices or Oracle DirectNFS. Sections Dell Unity file storage, Oracle Disk Manager, and Oracle Direct NFS discuss using the Dell Unity NFS service with Oracle DirectNFS.
The Dell Unity system supports a wide range of file systems on Linux. This section focuses on two popular and stable file systems: ext4 and xfs.
For additional information about supported file systems and feature limitations, see the Dell Technologies Host Connectivity Guide for Linux located on Dell Technologies E-Lab Navigator.
The file system can be created on top of a LUN, a LUN partition, or a logical volume in LVM. Dell Technologies recommends using the whole LUN without partition or a logical volume in LVM for ease of management.
It can be beneficial to separate the Oracle software and Oracle diagnostic logs. To separate software and logs, create a separate volume group or assign a different LUN to store Oracle diagnostic log files. The diagnostic logs can consume a large amount of space in a short time. By isolating the logs in a different file system, it reduces the risk of filling up the storage space with these logs and affects the operation of the software. Since the diagnostic logs are not mission critical to the software operation, it is not essential to enable snapshots on the LUNs used by the logs. The diagnostic logs are also good candidates to be compressed to reduce the storage consumption. Table 6 shows an example of using separate file systems for software and diagnostic logs.
Volume group | Logical volume | File system mount point | Dell Unity snapshot | Dell Unity compression |
vggrid | lv-grid-bin | /u01 | Enable | Disable |
vgoracle121 | lv-oracle-bin | /u01/app/oracle/product/21.0.x. | Enable | Disable |
vgoracle122 | lv-oracle-bin | /u01/app/oracle/product/21.1.x | Enable | Disable |
vgoraclelog | lv-grid-log | /u01/app/grid/diag | Disable | Enable |
lv-oracle-log | /u01/app/oracle/diag | Disable | Enable |
When mounting a file system, consider the following options and guidelines.
# blkid /dev/vgoracle/lv-oracle-rac-home
/dev/vgoracle/lv-oracle-rac-home: UUID="83cf5726-f842-448b-a143-5f77eb0d9b37" TYPE="xfs"
UUID="83cf5726-f842-448b-a143-5f77eb0d9b37" /u01 xfs defaults,discard,nofail 0 0
Certain file system types, such as ext4 and xfs, support the online resize operation. The following outlines the general steps to resize a file system online assuming non-partition LUN are used.
# rescan-scsi-bus.sh –resize
# multipathd -k"resize map orabin-rac"
For PowerPath, the new size is automatically updated.
# lvresize –L $NEW_SIZE /dev/vgoracle/lv-oracle-rac-home
# xfs_growfs –d /u01 (for xfs)
# resize2fs /dev/mapper/orabin-rac (for ext4)
For file system types that support the online SCSI TRIM/UNMAP command, enable the discard mount option in /etc/fstab or include –o discard to the manual mount command. The discard option allows space to be released back to the storage pool in the Dell Unity system when deleting files in the file system. Administrators should review the file system documentation to confirm the availability of the features.
The LUNs must be thin provisioned in Dell Unity storage system for space reclamation to work. As new data is written to the file system, space is allocated in the Dell Unity system. When files are deleted from the file system, the operating system informs the Dell Unity system which data blocks can be released. The release of storage is automatic and requires no additional steps. To confirm the release of space in the Dell Unity system, monitor the Total Pool Space Used on the LUN properties page in Unisphere.