db2ckbkp - Check backup command

Authorization

Anyone can access the utility, but users must have read permissions on image backups in order to execute this utility against them.

Required connection

None

Command syntax

>>-db2ckbkp--+---------------------------------+---------------->
             | .-,---------------------------. |   
             | V                             | |   
             +---+-------------------------+-+-+   
             |   +- -a---------------------+   |   
             |   +- -c---------------------+   |   
             |   +- -d---------------------+   |   
             |   +- -e---------------------+   |   
             |   +- -h---------------------+   |   
             |   +- -l---------------------+   |   
             |   +- -n---------------------+   |   
             |   +- -o---------------------+   |   
             |   +- -p---------------------+   |   
             |   +- -s---------------------+   |   
             |   +- -t---------------------+   |   
             |   +- -v---------------------+   |   
             |   +- -cl--decompressionLib--+   |   
             |   '- -co--decompressionOpts-'   |   
             +- -H-----------------------------+   
             +- -S-----------------------------+   
             '- -T-----------------------------'   

   .-,--------.   
   V          |   
>----filename-+------------------------------------------------><

Command parameters

-a

Displays all available information.

-c

Displays results of checkbits and checksums.

-d

Displays information from the headers of DMS table space data pages.

-e

Extracts pages from an image to a file. To extract pages, you will need an input and an output file. The default input file is called extractPage.in. You can override the default input file name by setting the DB2LISTFILE environment variable to a full path. The format of the input file is as follows:

For SMS table spaces:

  S <tbspID> <objID> <objType> <startPage> <numPages>

Note:

1. <startPage> is an object page number that is object-relative.

For DMS table spaces:

  D <tbspID> <objType> <startPage> <numPages>

Note:

1. <objType> is only needed if verifying DMS load copy images.
2. <startPage> is an object page number that is pool-relative.

For log files:

   L <log num> <startPos> <numPages>

For other data (for example, initial data):

   O <objType> <startPos> <numBytes>

The default output file is extractPage.out. You can override the default output file name by setting the DB2EXTRACTFILE environment variable to a full path.

-h

Displays media header information including the name and path of the image expected by the restore utility.

-l

Displays log file header (LFH) and mirror log file header (MFH) data.

-n

Prompt for tape mount. Assume one tape per device.

-o

Displays detailed information from the object headers.

-p

Displays the number of pages of each object type. This option will not show the number of pages for all different object types if the backup was done for DMS table spaces data. It only shows the total of all pages as SQLUDMSTABLESPACEDATA. The object types for SQLUDMSLOBDATA and SQLUDMSLONGDATA will be zero for DMS table spaces.

-s

Displays the automatic storage paths in the image.

-t

Displays table space details, including container information, for the table spaces in the image.

-v

Performs additional DMS and AS tablespace page validation. This option is not implied or enabled by the -a (all) option.

-cl decompressionLib

Indicates the name of the library to be used to perform the decompression. The name must be a fully qualified path referring to a file on the server. If this parameter is not specified, DB2® will attempt to use the library stored in the image. If the backup was not compressed, the value of this parameter will be ignored. If the specified library cannot be loaded, the operation will fail.

-co decompressionOpts

Describes a block of binary data that will be passed to the initialization routine in the decompression library. DB2 will pass this string directly from the client to the server, so any issues of byte reversal or code page conversion will have to be handled by the decompression library. If the first character of the data block is '@', the remainder of the data will be interpreted by DB2 as the name of a file residing on the server. DB2 will then replace the contents of string with the contents of this file and will pass this new value to the initialization routine instead. The maximum length for string is 1024 bytes.

-H

Displays the same information as -h but only reads the 4K media header information from the beginning of the image. It does not validate the image. This option cannot be used in combination with any other options.

-S

Displays the same information as -s but does not validate the image. This option cannot be used in combination with any other options.

-T

Displays the same information as -t but does not validate the image. This option cannot be used in combination with any other options.

filename

The name of the backup image file. One or more files can be checked at a time.

Note:

1. If the complete backup consists of multiple objects, the validation will only succeed if db2ckbkp is used to validate all of the objects at the same time.
2. When checking multiple parts of an image, the first backup image object (.001) must be specified first.

Usage notes

1. If a backup image was created using multiple sessions, db2ckbkp can examine all of the files at the same time. Users are responsible for ensuring that the session with sequence number 001 is the first file specified.
2. This utility can also verify backup images that are stored on tape (except images that were created with a variable block size). This is done by preparing the tape as for a restore operation, and then invoking the utility, specifying the tape device name. For example, on Linux and UNIX operating systems:

      db2ckbkp -h /dev/rmt0

   and on Windows:

      db2ckbkp -d \\.\tape1

3. If the image is on a tape device, specify the tape device path. You will be prompted to ensure it is mounted, unless option -n is given. If there are multiple tapes, the first tape must be mounted on the first device path given. (That is the tape with sequence 001 in the header).
   The default when a tape device is detected is to prompt the user to mount the tape. The user has the choice on the prompt. Here is the prompt and options: (where the device I specified is on device path /dev/rmt0)

       Please mount the source media on device /dev/rmt0. 
       Continue(c), terminate only this device(d), or abort this tool(t)? 
       (c/d/t) 

   The user will be prompted for each device specified, and when the device reaches the end of tape.