mkmf

Purpose

Use the mkmf command to make a new media family, which is a named classification of backup volumes. A media family ensures that volumes created at different times have similar characteristics. For example, you can create a media family for backups with a six-month retention period. If you specify this family on successive backup commands, then all created volumes have a six-month retention period.

A media family has either of the following types of mutually exclusive expiration policies: content-managed (default) or time-managed. In a content-managed policy, volumes expire only when all backup pieces recorded on a volume have been marked as deleted. In a time-managed policy, volumes expire when they reach the expiration time, which is calculated as the sum of the --writewindow time, the --retain time, and the volume creation time.

Prerequisites

You must have the modify administrative domain's configuration right to use the mkmf command.

Syntax

mkmf::=

mkmf [ --writewindow/-w duration ] [ --retain/-r duration ]
[ [ --vidunique/-u ] | 
  [ --vidfile/-F vid-pathname ] |
  [ --viddefault/-d ] | 
  [ --vidfamily/-f media-family-name ] ]
[ [ --inputcomment/-i | 
  [ --comment/-c comment ] ]
[ --contentmanaged/-C ] [ --append/-a ] [ --noappend/-A ]
media-family-name ...

Semantics

--writewindow/-w duration

Specifies a write-allowed time period for the media family. Refer to "duration" for a description of the duration placeholder. The default is disabled, which means that Oracle Secure Backup does not consider the write window when computing the volume expiration time.

A write window is the period of time for which a volume set remains open for updates, usually by appending backup images. All volumes in the family are considered part of the same volume set. The write window opens when the first file is written to the first volume in the set and closes after the specified period of time elapses. When the write window closes, Oracle Secure Backup disallows further updates to the volume set until one of the following conditions is met:

• It expires.

• It is relabeled.

• It is reused.

• It is unlabeled.

• It is forcibly overwritten.

Oracle Secure Backup continues using the volume set for backup operations until the write window closes.

Note that if you select forever or disabled as a duration, then you cannot enter a number. For example, you can set the write window as 14days or specify forever to make the volume set eligible to be updated indefinitely. All volume sets that are members of the media family remain open for updates for the same time period.

--retain/-r duration

Specifies the retention period, which is amount of time to retain the volumes in the volume set. By specifying this option, you indicate that this media family is time-managed rather than content-managed. Refer to "duration" for a description of the duration placeholder.

The volume expiration time is the date and time on which a volume expires. Oracle Secure Backup computes this time by adding the write window duration (--writewindow), if it is specified, to the time at which it wrote backup image file number 1 to a volume, and then adding the volume retention time (--retain).

The retention period prevents you from overwriting any volume included as a member of this media family until the end of the specified time period. If one volume becomes full, and if Oracle Secure Backup continues the backup onto subsequent volumes, then it assigns each volume in the volume set the same retention time.

You can make RMAN backups to time-managed volumes. Thus, volumes with a time-managed expiration policy can contain a mixture of file system and RMAN backup pieces.

Caution:

If you make RMAN backups to time-managed volumes, then it is possible for a volume to expire and be recycled while the RMAN repository reports the backup pieces as available. In this case, you must use the CROSSCHECK command in RMAN to resolve the discrepancy.

Note that you can change a media family from time-managed to content-managed by specifying --contentmanaged on the chmf command.

--vidunique/-u

Creates a volume ID unique to this media family. The volume ID begins with the string media-family-name-000001 and increments the volume sequence number each time it is used. For example, MYVOLUME-000001 would be the volume ID for the first volume in the MYVOLUME media family, MYVOLUME-000002 would be the ID for the second volume, and so forth.

--vidfile/-F vid-pathname

Specifies the name of the volume sequence file for the media family that you are creating. Specify either a relative filename, in which case the file is created in the administrative directory on the administrative server, or an absolute filename.

Because Oracle Secure Backup does not create this file automatically, you must create it manually. If you select the --vidfile option, then use a text editor to customize the vid- prefix. Enter the first volume ID to be assigned to the media family as a single line of text, for example, MYVOLUME-000001.

--viddefault/-d

Specifies the system default, that is, Oracle Secure Backup uses the same volume ID sequencing that it would use if no media family were assigned. The default volume ID begins at VOL000001 and increments each time it is used.

--vidfamily/-f media-family-name

Uses the same volume ID sequencing as is used for the media family identified by media-family-name.

--inputcomment/-i

Allows input of an optional comment for the media family.

--comment/-c comment

Specifies information that you want to store with the media family. If you choose to embed blanks in the comment, then surround the comment with quotes.

--contentmanaged/-C

Specifies that volumes in this media family are content-managed rather than time-managed. Volumes that use this expiration policy are intended for RMAN backups: you cannot write a file system backup to a content-managed volume.

A content-managed volume is eligible to be overwritten when all backup image sections have been marked as deleted. You can delete backup pieces through Recovery Manager or through the rmpiece command in obtool. A volume in a content-managed volume set can expire even though other volumes in the same set are not expired.

Note that you can change a media family from content-managed to time-managed by specifying --retain on the chmf command.

--append/-a

Specifies that additional backup images can be appended to volumes in the media family (default).

Although a volume may be unexpired and have tape remaining, Oracle Secure Backup will not write to a volume that is lower than the most recent volume sequence number for the media family. Every backup tries to append to the most recent volume in the media family; if this volume is full, then it writes to a new one.

--noappend/-A

Specifies that additional backup images cannot be appended to volumes in the media family. This option ensures that a volume set contains only a single backup image, which is useful if you perform a full backup and then use the tapes to re-create the original file system.

media-family-name ...

Specifies the name of the media family to create. Media family names are case-sensitive and must start with an alphanumeric character. They can contain only letters, numerals, dashes, underscores, and periods (no spaces). They may contain at most 31 characters.

Examples

Example 2-89 creates a time-managed media family called time-man-family. Volumes in the volume set are available for update for 7 days. Because the retention period is 28 days, a volume in the media family expires 35 days after Oracle Secure Backup first writes to it.

ob> mkmf --vidunique --writewindow 7days --retain 28days time-man-family

Example 2-90 creates a content-managed media family called content-man-family. Because the write window is forever, volumes in this family are eligible for update indefinitely. Volumes only expire when RMAN shows the status of all backup pieces on the volumes as DELETED.

ob> mkmf --vidunique --writewindow forever content-man-family