Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Managing System Security
Guidelines for Running a Secure System
Chapter 8778
• Daily incremental and full weekly backups are recommended.
Synchronize your backup schedule with the information flow in your
organization. For example, if a major database is updated every
Friday, you might want to schedule your weekly backup on Friday
evenings.
• If all files must be backed up on schedule, request that all users log
off before performing the backup. However, fbackup warns you if a
file is changing while the backup is being performed.
• Examine the log file of latest backups to identify problems occurring
during backup. The backup log file should have restrictive
permissions set.
• frecover allows you to overwrite a file. However, the file retains the
permissions and ACLs set when the file was backed up.
• You must test your recovery process beforehand to make sure you
can fully recover data in the event of an emergency.
• When recovering files from another machine, you might have to
execute the chown command to set the user ID and group ID for the
system on which they now reside, if the user and group do not exist
on the new system. If files are recovered to a new system that does
not have the specified group, the files will take on the group
ownership of the person running frecover. If owner and group
names have different meanings on different systems, recovery
results might be unexpected.
• Power failure should not cause file loss. However, if someone reports
a lost file after a power failure, look for it in /lost+found before
restoring it from a backup tape.
• To verify contents of the tape being recovered, use the -I option of
frecover to preview the index of files on the tape. Note, however,
that existing permissions of a file system are kept intact by the
backup; frecover prevents you from reading the file if the
permissions on the file forbid it.
• Never recover in place any critical files such as /etc/passwd, or
those in /tcb/files. Instead, restore the file to a temporary
directory (do not use /tmp) and give this directory permissions
drwx------, preventing anyone else from using it. Compare the
restored files with those to be replaced. Make any necessary changes.