Oracle Memory Speed CLI Commands

About Oracle Memory Speed CLI Commands

The omsfscmds utility administers Oracle Memory Speed (OMS) and requires the OMS daemon to be running. Set ORACLE_SID to the daemon’s SID before launching the utility from $ORACLE_HOME/bin; the OMS> prompt indicates successful startup.

mkfs and forcemkfs Command Reference

Use mkfs or forcemkfs to format an OMS uber file on a PMEM DAX mount point, optionally specifying a block size; only 4 KB is currently supported. The uber file size must be an exact multiple of 2 MB and cannot be mounted during formatting. mkfs rejects an existing OMS file system, whereas forcemkfs overwrites it without checking, permanently destroying its data.

mount, unmount and lsmount Command Reference

Use mount to attach an OMS uber file to an existing POSIX directory, umount to detach a mounted OMS file system, and lsmount to list mount points. A previously mounted uber file cannot be mounted again, OMS supports up to two mount points, and mount directories must exist and should not be writable.

df Command Reference

The df command reports the total, used, and free space in a mounted OMS file system. Its output is expressed in kilobytes and provides the capacity and current utilization for the specified mount path.

cp Command Reference

The cp command copies files between POSIX and OMS mount points, within one OMS mount point, or between OMS mount points associated with the same SID. Files in OMS require absolute paths, and cp is available only while the Oracle instance is down; Oracle recommends using SQL commands for file transfers while the instance is running.

ls and lls Command Reference

Use ls to list files in an OMS mount point and lls to display detailed file metadata, including blob number, size, block size, database ID, and directory ID. lls provides accurate allocated-byte totals, while ls may not accurately account for allocated space.

rm Command Reference

The rm command deletes a file from an OMS mount point using its absolute path. It is available only when the Oracle instance is down, deleted files cannot be restored, and removing critical files can prevent the instance from starting.

cd and pwd Command Reference

Use cd to set the current OMS working directory and pwd to display it. After changing the working directory, commands such as ls can operate without an explicit mount path.

lsom and lsof Command Reference

The lsom diagnostic operation lists Oracle process identifiers and the OMS files they have open, while lsof lists process identifiers holding a specified file open. These operations require the Oracle instance to be running, write results to a specified dump file, and require the alert log to map Oracle process identifiers to operating-system process IDs.

Daemon Control Command Reference

The daemon command controls the OMS daemon: daemon exit marks the shared memory segment for deletion and requests a clean daemon shutdown, while trace changes daemon trace verbosity to low, medium, or high, with medium as the default. Diagnostic trace files are stored under the OMS directory within the Oracle diagnostic destination.

Diagnostics and Tracing

The dump command provides diagnostic subcommands for printing OMS information, and the trace command traces internal OMS modules. Oracle technical support should be consulted before using these diagnostic and tracing options.
Read More: Diagnostics and Tracing