fbackup

[Nsikan_2]

Hi all,
Can fbackup be used to do incremental backups? How can this be done?
Please treat as very urgent.
Nsi.

[Pete Randall · Accepted solution]

From the man page:

If fbackup is used for incremental backups, a database of past backups
must be kept. fbackup maintains this data in the text file
/var/adm/fbackupfiles/dates, by default. Note that the directory
/var/adm/fbackupfiles must be created prior to the first time fbackup
is used for incremental backups. The -d option can be used to specify
an alternate database file.


. . .

-d path This specifies a path to a database for use with
incremental backups. It overrides the default database
file /var/adm/fbackupfiles/dates.



. . .


-0-9 This single-digit number is the backup level. Level 0
indicates a full backup. Higher levels are generally
used to perform incremental backups. When doing an
incremental backup of a particular graph at a
particular level, the database of past backups is
searched to find the date of the most recent backup of
the same graph that was done at a lower level. If no
such entry is found, the beginning of time is assumed.
All files in the graph that have been modified since
this date are backed up.



. . .



The second example is more complicated, and assumes the user wants to
maintain a database of past fbackup sessions so that incremental
backups are possible.

If sufficient on-line storage is available, it may be desirable to
keep several of the most recent index files on disk. This eliminates
the need to recover the index from the backup media to determine if
the files to be recovered are on that set. One method of maintaining
on-line index files is outlined below. The system administrator must
do the following once before fbackup is run for the first time
(creating intermediate level directories where necessary):

+ Create a suitable configuration file called config in the
directory /var/adm/fbackupfiles.

+ Create a graph file called usr-usrlib in the directory
/var/adm/fbackupfiles/graphs.

+ Create a directory called usr-usrlib in the directory
/var/adm/fbackupfiles/indices.
A shell script that performs the following tasks could be run for each
fbackup session:

+ Build an index file path name based on both the graph file
used (passed as a parameter to the script) and the start time
of the session (obtained from the system). For example:

/var/adm/fbackupfiles/indices/usr-usrlib/871128.15:17
(for Nov 28, 1987 at 3:17 PM)

+ Invoke fbackup with this path name as its index file name.
For example:

cd /var/adm/fbackupfiles
/usr/sbin/fbackup -0uc config -g graphs/usr-usrlib -I indices/usr-usrlib/871128.15:17 -f /dev/rmt/c0t0d0BEST

When the session completes successfully, the index is automatically
placed in the proper location.




In other words, check the man page for fbackup.


Pete

[Sridhar Bhaskarla]

Hi Nsi,

Yes. You can use it to do incremental backups.

Include the options -0 to -9 in your regular fbackup command to specify the level of increment. 0 is full backup. When you specify a higher number, it will look for the recent lowest level of backup and backups files only that got modified since then. You will need to ensure you use the same 'graph' file.

Look at 'fbackup' man page for more information.

-Sri

[Darren Prior]

Hi,

In addition to the good answers above, remember that incremental backups only work if all the following conditions are true:

* the directory for the dates file specified in the -d option (or /var/adm/fbackupfiles otherwise) already exists

* you use the -u option

* you use a graph file (in a fixed location), ie not using -i, -e options. The location of the graph file is must be fixed as it is read from the dates file for comparison when you make the incremental backup.

* the lower level backup completed successfully otherwise it won't have written to the dates file.

regards,

Darren