Kbase 15475: Basic Functionality of Progress Backup and Restore
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/05/1998 |
|
Basic Functionality of Progress Backup and Restore
How Progress Backup (probkup) works:
- Create a backup header which contains information describing the
backup and write that to the tape. One of the items the header
includes is the size of the database.
- Allocate the -bf number of blocks in memory (default is 30)
- Read the database blocks. At this time a verification that the
block is correct takes place. If the verification fails, then an
error, such as 1124, is posted. If the verification is successful
then the block is placed into the -bf buffer.
- Once the -bf buffer is full, write out the buffer to the tape.
- The last 2 steps are repeated until the backup is complete.
How Progress Restore (prorest) works:
- Read the backup header.
- Grow the target database to the size of the database on tape
(if needed)
- Read -bf (gotton from the backup header) number of blocks from the
tape and loop through the blocks, writing them to the target
database.
- The last step is repeated until the restore is complete.
Note: The blocking facter referred to is Progress Blocks, not OS
file system blocks. On most systems, the Progress Block is 1024
bytes. Please refer to knowledgebase 11930 for more information on
database block size.
Progress Software Technical Support Note # 15475