Creating and Working with Snapplans Using dbed_vmchecksnap
A snapplan specifies snapshot scenarios for an Oracle database (such as online, instant, or offline). You can name a snapplan file whatever you choose. You can use the dbed_vmchecksnap -o setdefaults option to create the snapplan and set default values for the parameters. You may then modify the snapplan file using a text editor.
You can also use the command to validate, copy, list, or remove a snapplan and check the storage to make sure it is configured appropriately for the Database FlashSnap feature. For more information on snapplans, see Validating a Snapplan (dbed_vmchecksnap).
Note
You must have the Enterprise Edition of VERITAS Storage Foundation for Oracle to use this command.
Snapplan Parameters
When using dbed_vmchecksnap -o setdefaults option to create the snapplan, the following parameters are set:
| Parameter
|
Value
|
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SNAPSHOT_VERSION
|
Specifies the snapshot version for this release of VERITAS Storage Foundation for Oracle
|
PRIMARY_HOST
|
Specifies the name of the host where the primary database resides.
|
SECONDARY_HOST
|
Specifies the name of the host where the clone database will reside. If the primary and secondary hosts are the same, the snapshot volumes will not be deported.
|
PRIMARY_DG
|
Specifies the name of the Volume Manager disk group used by the primary database.
|
SNAPSHOT_DG
|
Specifies the name of the disk group containing the snapshot volumes.
The snapshot volumes will be put into this disk group on the primary host and deported if the primary and secondary hosts are different. The secondary host will import this disk group to start a clone database.
|
ORACLE_SID
|
The name of the Oracle database.
|
ARCHIVELOG_DEST
|
Specifies the full path of the archive logs.
There are several archive log destinations that can be used for database recovery if you are multiplexing the archive logs. You must specify which archive log destination to use.
It is recommended that you have the archive log destination on a separate volume if SNAPSHOT_ARCHIVE_LOG is yes.
|
SNAPSHOT_ARCHIVE_LOG
|
yes or no
Specifies whether to create a snapshot of the archive log volumes. Specify yes to split the archive log volume mirrors and deport them to the secondary host. When using the Oracle remote archive log destination feature to send the archive logs to the secondary host, you can specify no to save some space.
Because the archive logs may not always be delivered to the secondary host reliably, it is recommended that you specify yes.
|
SNAPSHOT_MODE
|
online or offline or instant
Specifies whether the database snapshot should be online, offline, or instant.
If the snapshot is created while the database is online, the dbed_vmsnap command will put the tablespaces into backup mode. After dbed_vmsnap finishes creating the snapshot, it will take the tablespaces out of backup mode, switch the log files to ensure that the extra redo logs are archived, and create a snapshot of the archived logs.
If the database if offline, it is not necessary to put the tablespaces into backup mode.
If the snapshot mode is instant, a snapshot will be taken regardless of whether the database is online or offline. If it is online dbed_vmsnap will skip putting the tablespace into backup mode.
Note If SNAPSHOT_MODE is set to offline or instant, a two-host configuration is required and the -r relocate_path option is not allowed.
|
SNAPSHOT_PLAN_FOR
|
The default value is database and cannot be changed.
Specifies the database object for which you want to create a snapshot.
|
SNAPSHOT_PLEX_TAG
|
Specifies the name of the tag set to the plexes that will be used by dbed_vmsnap to take the snapshot. The dbed_vmchecksnap command will use this tag name to search if all the volumes in the database have the plexes with this tag name set.
By default, SNAPSHOT_PLEX_TAG=dbed_flashsnap.
|
SNAPSHOT_VOL_PREFIX
|
Specifies the snapshot volume prefix. Use this variable to specify a prefix for the snapshot volumes split from the primary disk group. A volume name cannot be more than 32 characters.
|
ALLOW_REVERSE_RESYNC
|
yes or no
By default, reverse resynchronization is off (set equal to no). If it is set to yes, this parameter allows you to restore the original volume from a snapshot. The original database, however, must be down for this operation.
|
SNAPSHOT_MIRROR
|
Specifies the number of plexes to be snapshot. The default value is 1.
|
Creating a Snapplan
Prerequisites
- You must be the Oracle database administrator.
- The disk group must be version 110 or later. For more information on disk group versions, see the vxdg(1M) manual page.
- Be sure that a DCO and DCO volume are associated with the volume for which you are creating the snapshot.
- Snapshot plexes and their associated DCO logs should be on different disks than the original plexes, and should be configured correctly for creating snapshots by the system administrator.
- Persistent FastResync must be enabled on the existing database volumes and disks must be assigned for the snapshot volumes.
- The database must be running in archive log mode. Archive log mode is set in the Oracle initialization parameter file (init.ora).
- ORACLE_HOME cannot reside on disk which will be used for snapshot.
- QuickLog must be disabled before creating a snapplan.
Usage Notes
- The snapplan must be created on the primary host.
- After creating the snapplan using the dbed_vmchecksnap command, you can use a text editor to review and update the file, if necessary.
- It is recommended that you create a local working directory to store your snapplans in.
- See the dbed_vmchecksnap(1M) online manual page for more information.
- If the SNAPSHOT_MODE for the database is set to online, the primary and secondary hosts can be the same. If the SNAPSHOT_MODE is set to offline or instant, the primary and secondary hosts must be different.
Options
-S
|
Specifies the ORACLE_SID, which is the name of the Oracle database, for which a snapshot image will be created.
|
-H
|
Specifies the Oracle home directory that corresponds to the ORACLE_SID.
|
-f SNAPPLAN
|
Specifies the local path or the full path of the snapplan that you are creating.
|
-o setdefaults
|
Creates a default snapplan. This option can be used with the -o validate option to validate that the configuration is correct. See Summary of Database Snapshot Steps for descriptions of the snapplan parameters.
|
-o validate
|
Validates each parameter in the snapplan and checks whether the snapshot volumes have been configured correctly for creating snapshots, and copies the snapplan to the repository.
|
-o list
|
Lists all the snapplans associated with a specific $ORACLE_SID.
|
-o copy
|
Copies the snapplan from the repository to your current local directory.
|
-o remove
|
Removes the snapplan from the repository and your local directory.
|
-t SECONDARY_HOST
|
Specifies the name of the host to which the snapshot image will be deported. If it is the same as the primary server, the snapshot volumes will not be deported. This argument is required if -o setdefaults is used. It is ignored if specified for -o validate.
|
[-p PLEX_TAG]
|
Specifies the tag name for the plexes used to create the snapshot. If it is not specified, dbed_flashsnap is used as the default plex tag.
|
To create a snapplan and set the default values for a single host
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -H /oracle/product/9i \
-f snap1 -o setdefaults -t host1
SNAPSHOT_VERSION=4.0
PRIMARY_HOST=host1
SECONDARY_HOST=host1
PRIMARY_DG=PRODdg
SNAPSHOT_DG=SNAP_PRODdg
ORACLE_SID=PROD
ARCHIVELOG_DEST=/prod_ar
SNAPSHOT_ARCHIVE_LOG=yes
SNAPSHOT_MODE=online
SNAPSHOT_PLAN_FOR=database
SNAPSHOT_PLEX_TAG=dbed_flashsnap
SNAPSHOT_VOL_PREFIX=SNAP_
ALLOW_REVERSE_RESYNC=no
SNAPSHOT_MIRROR=1
To create a snapplan and set the default values in a two-host configuration
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD \
-H /oracle/product/9i -f snap2 -o setdefaults -t host2
Snapplan snap2 for PROD.
=====================================================
SNAPSHOT_VERSION=4.0
PRIMARY_HOST=host1
SECONDARY_HOST=host2
PRIMARY_DG=PRODdg
SNAPSHOT_DG=SNAP_PRODdg
ORACLE_SID=PROD
ARCHIVELOG_DEST=/mytest/arch
SNAPSHOT_ARCHIVE_LOG=yes
SNAPSHOT_MODE=online
SNAPSHOT_PLAN_FOR=database
SNAPSHOT_PLEX_TAG=dbed_flashsnap
SNAPSHOT_VOL_PREFIX=SNAP_
ALLOW_REVERSE_RESYNC=no
SNAPSHOT_MIRROR=1
Validating a Snapplan
You can use the the dbed_vmchecksnap command with the -o validate option to validate a snapplan and check the storage to make sure it is configured appropriately for the Database FlashSnap feature.
To validate a snapplan for a snapshot image to be used on the primary host
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -H /oracle/product/9i \
-f snap1 -o validate
PRIMARY_HOST is host1
SECONDARY_HOST is host1
The version of PRIMARY_DG-PRODdg is 110.
SNAPSHOT_DG is SNAP_PRODdg
SNAPSHOT_MODE is online
The database is running in archivelog mode.
ARCHIVELOG_DEST is /prod_ar
SNAPSHOT_PLAN_FOR is database
SNAPSHOT_ARCHIVE_LOG is yes
ARCHIVELOG_DEST=/prod_ar is mount on /dev/vx/dsk/PRODdg/prod_ar.
Examining Oracle volume and disk layout for snapshot
Volume prod_db on PRODdg is ready for snapshot.
Original plex and DCO log for prod_db is on PRODdg01.
Snapshot plex and DCO log for prod_db is on PRODdg02.
SNAP_PRODdg for snapshot will include: PRODdg02
ALLOW_REVERSE_RESYNC is yes
The snapplan snap1 has been created.
To validate a snapplan for a snapshot image to be used on the secondary host
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -H \
/oracle/product/9i -f snap2 -o validate
PRIMARY_HOST is host1
SECONDARY_HOST is host2
The version of PRIMARY_DG-PRODdg is 110.
SNAPSHOT_DG is SNAP_PRODdg
SNAPSHOT_MODE is online
The database is running in archivelog mode.
ARCHIVELOG_DEST is /mytest/arch
SNAPSHOT_PLAN_FOR is database
SNAPSHOT_ARCHIVE_LOG is yes
ARCHIVELOG_DEST=/mytest/arch is mount on /dev/vx/dsk/PRODdg/arch.
Examining Oracle volume and disk layout for snapshot.
Volume prod_db on PRODdg is ready for snapshot.
Original plex and DCO log for prod_db is on PRODdg01.
Snapshot plex and DCO log for prod_db is on PRODdg02.
SNAP_PRODdg for snapshot will include: PRODdg02
ALLOW_REVERSE_RESYNC is yes
The snapplan snap2 has been created.
Listing and Viewing Snapplans Using dbed_vmchecksnap
To list all available snapplans for a specific Oracle database
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -o list
The following snapplan(s) are available for PROD:
SNAP_PLAN SNAP_STATUS DB_STATUS SNAP_READY
snap1 init_full init yes
snap2 init_full init yes
snap3 init_full init yes
Note
The command output displays all available snapplans, their snapshot status (SNAP_STATUS), database status (DB_STATUS), and whether a snapshot may be taken (SNAP_READY). For explanations of the various statuses that may appear for SNAP_STATUS and DB_STATUS, refer to VERITAS Database FlashSnap Status Information.
To view a snapplan
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -f snap1 -o list
SNAPSHOT_VERSION=4.0
PRIMARY_HOST=host1
SECONDARY_HOST=host1
PRIMARY_DG=PRODdg
SNAPSHOT_DG=SNAP_PRODdg
ORACLE_SID=PROD
ARCHIVELOG_DEST=/prod_ar
SNAPSHOT_ARCHIVE_LOG=yes
SNAPSHOT_MODE=online
SNAPSHOT_PLAN_FOR=database
SNAPSHOT_PLEX_TAG=dbed_flashsnap
SNAPSHOT_VOL_PREFIX=SNAP_
ALLOW_REVERSE_RESYNC=yes
SNAPSHOT_MIRROR=1
STORAGE_INFO
PRODdg02
SNAP_PLEX=prod_db-02 prod_ar-02
STATUS_INFO
SNAP_STATUS=init_full
DB_STATUS=init
LOCAL_SNAPPLAN=/export/snap_dir/snap1
Copying or Removing a Snapplan Using dbed_vmchecksnap
To copy a snapplan from the VxDBA repository to your local directory
To copy a snapplan from the VxDBA repository to your local directory, the snapplan must not already be present in your local directory.
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -f snap1 -o copy
Copying 'snap1' to '/export/snap_dir'
To remove a snapplan
Use the dbed_vmchecksnap command as follows:
$ /opt/VRTS/bin/dbed_vmchecksnap -S PROD -f snap1 -o remove
The snapplan snap1 has been removed from VxDBA repository.
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