Adaptive Server adds a cyclic redundancy check for accidental changes to raw data for
database or transaction dumps created with compression to check and for verification that
the compression blocks can be correctly read and decompressed.
The syntax
is:
dump database database_name to dump_device with compression=n,verify={crc | read_after_write}
load database database_name from dump_device with verify[only]=crc
Where:
- verify=crc – indicates that you are performing a cyclic
redundancy check.
- verify=read_after_write – Backup Server rereads every
compressed block after writing and decompresses it. If Backup Server finds an
error, it prints the offset in the file it finds the error.
verify=read_after_write is only applicable with the
dump database command.
This example verifies database
new_dump before dumping it to the
mydumpdev
device:
dump database new_dump to mydumpdev with compression=x,verify=read_after_write
This example performs a cyclic redundancy check as it loads the
new_dump
database
dump:
load database new_dump from mydumpdev with verify[only]=crc
If the database was not dumped with verify=crc, this option is
ignored
This example performs a cyclic redundancy check and rereads every compressed block before
dumping database
new_dump to the
mydumpdev
device:
dump database new_dump to mydumpdev with compression=x,verify=read_after_write, verify=crc
Usage:
- Dump created without the verify=crc parameter use the same
format as earlier versions of Backup Server.
- You cannot load dumps that include cyclic redundancy checks with versions of
Backup Server that do not include this functionality.
- verify={crc | read_after_write} checks are applicable only
for files created using the with compression parameter.
- verify=crc works with any file type, including raw devices,
disk files, tapes, pipes, or APIs. However,
verify=read_after_write requires a ‘seek back’ for
rereading the block, and is applicable only with raw devices and disk files.
- Adaptive Server ignores, and does not raise an error message, if you include
verify={crc | read_after_write} parameters that are not
applicable.