dbed_codm_adm - Manage cached ODM for datafiles

dbed_codm_adm -S ORACLE_SID -H ORACLE_HOME

1. Displaying current metric values

-o display [ -n num ] [ -c col ] [ -t tbs ]

2. Displaying average metrics during given time interval

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -d start_date end_date
-m start_time end_time ]
[ -b blocklist_file ]
[ datafile ]

3. Displaying average metrics during the interval between given AWR snapshots

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -u snapshot_range [ -u snapshot_range ] ]
[ -b blocklist_file ]
[ datafile ]

4. Displaying average metrics during the past few AWR snapshots

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -u num_snapshots ]
[ -b blocklist_file ] [ datafile ]

5. Blocklist management commands

-o add-to-blocklist { datafile | -f filelist }

-o remove-from-blocklist { datafile | -f filelist }

-o print-blocklist

6. Turning Cached ODM on or off and viewing status of Cached ODM

-o [ on | off | odmstats ] datafile | -f list_of_files

-o filestate [ datafile | -f list_of_files ]

7. Displaying ODM IO statistics

-o iostats

Veritas Storage Foundation.

To determine whether this product is installed on the system, enter:

 rpm -qa | grep VRTSdbed

The cached ODM admin tool is a command-line utility which allows the DBA to manage and display several aspects of the cached ODM feature of Veritas File System.

1. Displaying current metric values

-o display [ -n num ] [ -c col ] [ -t tbs ]

This form of the command displays the top 10 files (10 is the default) sorted on a a certain column of the v$filestat view of the database (the default sort column is v$filestat).

No guarantees are made about the improvement in performance of the database by selectively enabling cached ODM on the list of files generated by this tool.

The output list (of files) can be sorted on other columns too, by using the -c option listed below. This option is only for the convenience of the DBA to see some database file I/O statistics at a glance and decide for himself (based on other things) what files the DBA would like to enable/disable cached ODM for.

This is the only report that can be generated if periodic AWR snapshots are not configured on the database.

2. Displaying average metrics during given time interval

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -d start_date end_date
-m start_time end_time ]
[ -b blocklist_file ]
[ datafile ]

This form of the command generates a report of the candidate files ordered by the most likely candidate first. The advisory utility considers datafiles which have the most amount of physical read activity to be the most likely candidate for caching. This report requires that the database be configured to take regular AWR snapshots.

The generated report has the following columns:

o	Tablespace Name
o	Filename
o	Average Physical Reads per Snapshot
o	Average Physical Blocks Read per Snapshot
o	Read Time (in seconds)

If a datafile is specified, a report is generated for the read activity on that datafile. This report has the following columns:

o	Snapshot Id
o	Interval End Time
o	Physical Reads
o	Physical Blocks Read
o	Read Time (in seconds)

The generated report considers the read activity recorded on the datafiles during the specified time interval. The start date and end date must be specified in yyyy/mm/dd format. The start time and end time must be specified as the hour of the day in 24-hour format. The data considered for the report is from the AWR snapshots taken during the specified hour range on all of the days in the specified date range.

3. Displaying average metrics during the interval between given AWR snapshots

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -u snapshot_range [ -u snapshot_range ] ]
[ -b blocklist_file ]
[ datafile ]

This form of the command generates a report of the candidate files ordered by the most likely candidate first. The advisory utility considers datafiles which have the most amount of physical read activity to be the most likely candidate for caching. This report requires that the database be configured to take regular AWR snapshots.

The generated report has the following columns:

o	Tablespace Name
o	Filename
o	Average Physical Reads per Snapshot
o	Average Physical Blocks Read per Snapshot
o	Read Time (in seconds)

If a datafile is specified, a report is generated for the read activity on that datafile. This report has the following columns:

o	Snapshot Id
o	Interval End Time
o	Physical Reads
o	Physical Blocks Read
o	Read Time (in seconds)

The generated report considers the read activity recorded on the datafiles in the AWR snapshots in the specified range. The snapshot_range parameter must be specified in a start-snapshot-id-end-snapshot-id format. Both endpoints of the snapshot range are inclusive.

Providing two snapshot ranges using -u options generates a comparative report on a single datafile during the two intervals. This is helpful in comparing the read performance for a datafile before and after enabling Cached ODM. This comparison requires that a datafile name be provided.

4. Displaying average metrics during the past few AWR snapshots

-o display [ -n num ] [ -t tbs ] [ -p ] [ -a ]
[ -u num_snapshots ]
[ -b blocklist_file ] [ datafile ]

This form of the command generates a report of the candidate files ordered by the most likely candidate first. The advisory utility considers datafiles which have the most amount of physical read activity to be the most likely candidate for caching. This report requires that the database be configured to take regular AWR snapshots.

The generated report has the following columns:

o	Tablespace Name
o	Filename
o	Average Physical Reads per Snapshot
o	Average Physical Blocks Read per Snapshot
o	Read Time (in seconds)

If a datafile is specified, a report is generated for the read activity on that datafile. This report has the following columns:

o	Snapshot Id
o	Interval End Time
o	Physical Reads
o	Physical Blocks Read
o	Read Time (in seconds)

The generated report considers the read activity recorded on the datafiles during the past num_snapshots AWR snapshots. If the AWR snapshots are configured every hour, for example, the report will consider the read activity during the past num_snapshots hours.

5. Blocklist management commands

-o add-to-blocklist { datafile | -f filelist }

-o remove-from-blocklist { datafile | -f filelist }

-o print-blocklist

These forms of the command enable management of the blocklist files. The blocklist file provides a way to mark certain files as not being candidates for enabling Cached ODM. For every VxFS filesystem, the blocklist file is stored in the lost+found/odmadm-blocklist file in the filesystem. The -o display forms of the command also take a -b blocklist-file option that lets user specify an alternate blocklist file. If this option is provided, the default blocklist files are not consulted.

6. Turning Cached ODM on or off and viewing status of Cached ODM

-o [ on | off | odmstats ] datafile | -f list_of_files

-o filestate [ datafile | -f list_of_files ]

This form of the command allows the DBA to enable or disable cached ODM on a per file basis, and to view the per-file cached ODM status and I/O statistics. The statistics reported by the -o odmstats option are the same as for the odmstat utility. See the odmstat(1M) man page for more details.

The -o filestate option allows the DBA to display the current state of cached ODM for all the datafiles in use by Oracle or for the specific set of file(s) specified on the command line.

The datafile / list_file parameter is optional. If neither option is supplied, all the files in the database will be displayed with their cached ODM states.

7. Displaying ODM IO statistics

-o iostats

This form of the command displays some cached ODM I/O statistics which are the same as those displayed with the getiostats option to the odmadm utility.

-S ORACLE_SID	ORACLE_SID is the SID of the Oracle database to be used.
-H ORACLE_HOME	ORACLE_HOME is the HOME of the Oracle instance to be used.
-o [ on | off ] datafile | -f list of files	Turns on or off cached ODM for the file specified by <datafile> or for the set of files specified in the file <list of files>. the on/ off setting is persistently stored in a per-filesystem configuration file located in the lost+found directory of the VxFS filesystem on which the files are stored. Files that are not located on a VxFS file-system are skipped. The configuration file is a plain-text file and contains a single line per file and can be examined by the DBA to see the current settings as applied by this tool. However, the configuration file should not be directly edited and this tool should be used to alter the cached ODM setting. It is also important to note that the settings contained in this configuration file take precedence over any per-file settings contained in the cached ODM configuration file located at /etc/vx/odmadm. Since /etc/vx/odmadm configuration file is typically hosted on a local filesystem whereas the cached ODM admin tool configuration file is hosted on the VxFS filesystem itself, it is guaranteed that the settings contained in the cached ODM admin tool configuration file are applied across failover scenarios and to all the nodes in a CFS/RAC cluster configuration.
-c column_index	The File I/O statistics would be sorted on specified column index. This is an optional field. By default I/O statistics would be sorted on number of physical reads.
-n num	Used to change the default number of files displayed. Used this option together with a\k:^XXo display to show the top num files which are candidates for enabling Cached ODM
-f list_file	list_file contains a list of datafiles used by the Oracle database that you want to process
-t tablespace	Specify the tablespace for -o display option to display candidate files for certain tablespace.
-d start_date end_date	Specifies the date range for the report generated for the -o display option. The dates must be formatted in the yyyy/mm/dd format.
-m start_time end_time	Specifies the time range for the report generated for the -o display option. The times must be specified as the hour of day in 24-hour format.
-u snapshot_specifier	If the snapshot_specifier is a single number, it is taken as the number of recent AWR snapshots to consider when generating a report for the -o display option. If the snapshot_specifier is of the form start-snapshot-id-end-snapshot-id, it is taken as the range of AWR snapshots to consider when generating a report for the -o display option. In this form, the -u option may be given twice, in which case, a comparative report will be generated for the two intervals.
-b blocklist-file	Specifies an alternate file to use as the blocklist.
-a	By default, the report generated using the -o display option will exclude files that have Cached ODM enabled. If the -a option is specified, such files are also considered when generating the report.
-p	This option suppresses some of the tabular formatting in the reports generated using the -o display option. The output generated with the -p option is more suitable for programmatic processing.
datafile	Specify one datafile to be processed. With the -o display option, a detailed report is generated for a single datafile.

1. To show the top 15 files which has the highest Read I/O and Cached ODM has not been enabled yet for tablespace tbs1:

 $ dbed_codm_adm -S prod -H /orahome -o display -n 15 -t tbs1

2. To turn on cached ODM on the oracle datafile /oradata/test1.dbf:

 $ dbed_codm_adm -S prod -H /orahome -o on /oradata/test1.dbf

3. Following is the command option to display all the database files and their states.

 $ dbed_codm_adm -S prod -H /orahome -o filestate

4. To show ODM statistics for the datafile /oradata/tb1.dbf

 $ dbed_codm_adm -S prod -H /orahome -o odmstats /oradata/tb1.dbf

odmadm(1M), odmstat(1M)