The difference between a normal restore and a full system restore is the severity of
the problem. Normally, if data is lost or removed, it is recovered from the archives using
the normal restore procedures. However, when a normal restore operation cannot correct a
software and/or hardware corruption problem, some additional changes may be
required.
The level of system restore required may be different as described below.
When the database is corrupted and a restore is required, both the
application software and database must be restored. This can
be achieved by performing the following steps:
Restoring the application by using the file system iDataAgent
restore options.
Restoring the database files using the restore options in the
iDataAgent.
When the client system (operating system, hardware, hard drives, etc.) is
damaged or destroyed, a full system restore may be required.
The following procedure demonstrates how to perform a full system restore
when the client system is damaged or destroyed. The procedure assumes the
following:
Latest file system, Informix backups, ixbar file, and ONCONFIG
file are available.
File system backup does not include the Informix databases. (This
is done by filtering the entire dbspace directory.)
To
perform a full system restore:
If necessary, rebuild the hardware as it existed before.
Using the appropriate instructions, perform a full system restore of
your file system to rebuild your operating system. In
addition to restoring to your operating system, this operation will restore
the Informix application files and all of the iDataAgent
software.
Reboot the machine.
If there are any problems with the Informix iDataAgent
software, we recommend that you un-install and re-install the software
in the same drive where it was previously installed. Use the same
installation parameters, passwords, and backup type settings as were
previously used.
Use the directives in Create an Instance
to create a simple instance on the destination host. Ensure that you are
including the parameters that were used for the instance before the system
failure.
On the destination host, start up the instance and then shut down the
instance.
Log into the destination host and navigate to the $INFORMIXDIR/etc
directory. Then perform the following file copies (using
"cp"):
ixbar.$serevrnum to
ixbar.$servernum.org
onconfig.$servername to
onconfig.$servername.org
oncfg_$servername.$servernum to
oncfg_$servername.$servernum .org
Then use the directives in
Browse
and Restore to cross-restore the ixbar and onconfig files on the CommCell
Console from the source host's backups. Thereafter, modify the
onconfig.$servername.org file to be identical to the onconfig.$servername
file (i.e., ensure that DBSERVERNAME, SERVERNUM, and ROOTPATH are the
same).
Finally, copy the onconfig.$servername.org file to the onconfig.$servername
file.
Log into the destination host and prepare dbspaces that refer to the oncfg
files. All dbspaces physical paths have to be the same (e.g., prepare the
cooked file space, cat /dev/null > $INFORMIXDIR/dbs/test1/data/testdbs1.c1,
Try to restore the whole system by using the directives in
Browse
and Restore. It is recommended that you avoid
performing a salvage backup (e.g., zeroing out the root dbspace before
restoring or performing a physical whole system restore plus a logical whole
system restore).