Archive information in reserved pages

Technote (FAQ)


Question


How is backup information stored in the reserved pages?

Answer

When you run a backup with IBM Informix® Dynamic Server™ (IDS), information about the archive is stored in the reserved pages, located on the first 12 pages of the initial chunk of the root dbspace. To view these reserved pages you can use the oncheck -pr utility.

For more information about the reserved pages see the IDS Dynamic Server Administration Guide.

Depending on the utility you use for your backup, archive information is stored either in the two reserved pages called Archive Reserved Pages or in the two pages called Dbspace Reserved Pages. The ontape backup utility records the archive information in the Archive Reserved Pages called PAGE_1ARCH and PAGE_2ARCH. The onbar whole system backup records the archive information in the Archive Reserved Pages. The onbar backup utility records non-whole system archive information in the DBspace Reserved Pages called PAGE_1DBSP and PAGE_2DBSP when running a level 0, level 1, or level 2 backup.

Example

1) The ontape level 0 backup:

    $ ontape -s -L 0
In the online.log you will see this output:
    15:33:43  Level 0 Archive started on rootdbs, datadbs1, datadbs2
    15:33:44  Archive on rootdbs, datadbs1, datadbs2 Completed.


In the DBspace Reserved Pages you will see that the dbspace archive status information in DBspace Reserved Pages is not updated. The information in Archive Reserved Pages is updated and shows the new value.
    $ oncheck -pr

    Validating PAGE_1DBSP & PAGE_2DBSP...
              Using DBspace page PAGE_2DBSP.

        DBspace number                 1
        DBspace name                   rootdbs
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  11/29/2007 12:55:52
              Time Stamp Archive Began 23242673
              Logical Log Unique Id    1013
              Logical Log Position     0x6018

        DBspace number                 2
        DBspace name                   datadbs1
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  11/29/2007 12:55:52
              Time Stamp Archive Began 23242673
              Logical Log Unique Id    1013
              Logical Log Position     0x6018

        DBspace number                 3
        DBspace name                   datadbs2
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  11/29/2007 12:55:52
              Time Stamp Archive Began 23242673
              Logical Log Unique Id    1013
              Logical Log Position     0x6018

    Validating PAGE_1ARCH & PAGE_2ARCH...
              Using archive page PAGE_1ARCH.

        Archive Level                  0
        Real Time Archive Began        11/30/2007 15:33:14
        Time Stamp Archive Began       0x162e152
        Logical Log Unique Id          1013
        Logical Log Position           0x2a9018



2) The onbar level 0 backup:
    $ onbar -b -L 0

In the online.log you will see this output:
    14:21:14  Level 0 Archive started on rootdbs
    14:21:18  Archive on rootdbs Completed.
    14:21:19  Level 0 Archive started on datadbs1
    14:21:19  Level 0 Archive started on datadbs2
    14:21:20  Archive on datadbs2 Completed.
    14:21:20  Archive on datadbs1 Completed.


In the DBspace Reserved Pages you will see that the dbspace archive status information in DBspace Reserved Pages is updated and shows the new value. The Archive Reserved Pages will not change and still shows the old value.
    $ oncheck -pr

    V alidating PAGE_1DBSP & PAGE_2DBSP...
              Using DBspace page PAGE_1DBSP.

        DBspace number                 1
        DBspace name                   rootdbs
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:14
              Time Stamp Archive Began 23131742
              Logical Log Unique Id    996
              Logical Log Position     0x15c418

        DBspace number                 2
        DBspace name                   datadbs1
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:19
              Time Stamp Archive Began 23131815
              Logical Log Unique Id    996
              Logical Log Position     0x15f018

        DBspace number                 3
        DBspace name                   datadbs2
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:19
              Time Stamp Archive Began 23131815
              Logical Log Unique Id    996
              Logical Log Position     0x15f018

      Validating PAGE_1ARCH & PAGE_2ARCH...
              Using archive page PAGE_2ARCH.

         Archive Level                  0
        Real Time Archive Began        08/21/2007 12:18:15
        Time Stamp Archive Began       0x15f9bb7
        Logical Log Unique Id          988
        Logical Log Position           0x4418


3) The onbar whole system back up.
    $ onbar -b -w -L 0

In the online.log you will see this output:
    14:37:28  Level 0 Archive started on rootdbs, datadbs1, datadbs2
    14:37:32  Archive on rootdbs, datadbs1, datadbs2 Completed.

In the Reserved Pages you will see that the dbspace archive status information in DBspace Reserved Pages is not updated. Only the Archive Reserved Pages are updated and show the new value:
    $ oncheck -pr

    Validating PAGE_1DBSP & PAGE_2DBSP...
              Using DBspace page PAGE_1DBSP.

        DBspace number                 1
        DBspace name                   rootdbs
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:14
              Time Stamp Archive Began 23131742
              Logical Log Unique Id    996
              Logical Log Position     0x15c418

        DBspace number                 2
        DBspace name                   datadbs1
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:19
              Time Stamp Archive Began 23131815
              Logical Log Unique Id    996
              Logical Log Position     0x15f018

        DBspace number                 3
        DBspace name                   datadbs2
        ...
        DBspace archive status

              Archive Level            0
              Real Time Archive Began  09/28/2007 14:21:19
              Time Stamp Archive Began 23131815
              Logical Log Unique Id    996
              Logical Log Position     0x15f018

    Validating PAGE_1ARCH & PAGE_2ARCH...
              Using archive page PAGE_1ARCH.

        Archive Level                  0
        Real Time Archive Began        09/28/2007 14:37:28
        Time Stamp Archive Began       0x160f9e0
        Logical Log Unique Id          997
        Logical Log Position           0x6418

Rate this page:

(0 users)Average rating

Document information


More support for:

Informix Servers

Software version:

7.3, 9.4, 10.0, 11.1, 11.5

Operating system(s):

AIX, DYNIX/ptx, Digital Unix (OSF1)(TRU64), HP-UX, IRIX, Linux, Reliant UNIX, Sinix, Solaris, Windows

Reference #:

1273700

Modified date:

2008-08-11

Translate my page

Machine Translation

Content navigation