When advanced logging is enabled, use these recommendations for backup and recovery processes on your data files.
Enable advanced recovery logging for both rollforward and rollback recovery.
Advanced recovery logging provides a more flexible solution that basic logging when recovery is required.
fs /d dbase.ref /ltf <filename>.tlog /ltt f
You can disable logging for non-essential files by appending the following option to the command above:
/f filename /o l
Take regular backups.
Run a backup on (at least) a daily basis, which will start a new log file after each backup. Keeping the size of your log files relatively small will ensure that rollforward recovery will take less time to run.
Optimize hot backup times.
When taking a snapshot of the data files, the snapshot will be quicker if the data files being logged are stored on their own volume.
Where possible, use rollback recovery as your default recovery method.
Rollback recovery is quicker than rollforward recovery, but under certain circumstances, it may take longer (such as when a data scrape is required).
If a data scrape is required, the default action is to run it, but you can use fsexitproc.cbl to prevent large files from running a data scrape. Use the 78-file-recovery-rbld-strt clause to interrogate the size of the file (offset-x) and make the decision to perform the data scrape or skip to the next file. You must make a note of any files that are skipped, then perform rollforward recovery on those files.
When not to attempt the rollback recovery process.
Do not attempt rollback recovery if a system failure occurred and the cache failed to write to disk, unless you started Fileshare with the /lw (write through) and /fc (flush on commit) options; you can add these options to the Fileshare Server configuration file, but they will affect performance. If these options are not set, use rollforward recovery instead.
Only recover the necessary files.
After a rollback recovery, if some files were skipped and require rollforward recovery, you can use the 78-file-recovery clause in fsexitproc.cbl to again skip over non-essential files.