by Joe Hertvik
Being a complicated and
robust system, OS/400 offers several different save and restore
commands for backup protection of different system components.
Unfortunately, this wealth of options sometimes gets confusing, and it's
helpful to understand how the pieces of the puzzle fit together. To
that end, let's take a few minutes to look at the different components
of a typical OS/400 full system backup and how they relate to one
another.
The classic full system
backup is performed by selecting Option 21 (Entire System) from the GO
SAVE menu. (Note: Option 21 must be run from the system console.) Here's
a breakdown of all the steps Option 21 uses to save your system data to
media and how you can use selected restore commands to bring back
subsets of the data.
Step 1
Option 21 puts the system into restricted state by using the End Subsystem (ENDSBS) command, as follows:
ENDSBS SBS(*ALL) OPTION(*IMMED)
The ENDSBS command
shuts down all your iSeries or AS/400 subsystems, leaving only the
system console active for you to perform backups or other restricted
system chores on. (For more information on restricted state and how
ENDSBS works, see "Admin Alert: Getting In and Out of iSeries Restricted State.")
Step 2
Change the QSYSOPR
message queue to break or notify mode, for viewing tape drive messages
as your system is being backed up. Besides prompting for the proper tape
drive to which your system would back up, Option 21 prompts you to
automatically display or notify you of operator messages that occur
during your backup. Depending on how you answer the prompts, Option 21
will use one of the following Change Message Queue (CHGMSGQ) commands,
to change the QSYSOPR message to *BREAK or *NOTIFY mode for your job.
CHGMSGQ QSYSOPR DLVRY(*BREAK)
Or
CHGMSGQ QSYSOPR DLVRY(*NOTIFY)
Step 3
Save system and user
configuration data by using the Save System (SAVSYS) command. This
command saves three sets of data to your backup media: OS/400 licensed
internal code and OS/400 objects in the QSYS library; security data,
which includes user profiles and private authorities; and configuration
objects. Outside of Option 21, you could save your system's security
data separately by using the Save Security Data (SAVSECDTA) command. To
restore OS/400 security data from media, use the Restore User Profiles
(RSTUSRPRF) command for user profiles and the Restore Authority (RSTAUT)
command for private authorities. The configuration object save backs up
the same configuration data as the Save Configuration (SAVCFG) command,
and you would use the Restore Configuration (RSTCFG) command to restore
that data back to the system.
Step 4
Option 21 saves all libraries by using the Save Library (SAVLIB) command with the *NONSYS option, as follows:
SAVLIB LIB(*NONSYS) DEV(tape_drive_name) ACCPTH(*YES)
Using the *NONSYS
parameter is equivalent to running the following two SAVLIB statements
together, and by using SAVLIB *NONSYS, Option 21 saves both sets of data
at one time.
SAVLIB LIB(*IBM) DEV(tape_drive_name) SAVLIB LIB(*ALLUSR) DEV(tape_drive_name)
*IBM libraries include
all OS/400 optional libraries--such as QHLPSYS and QUSRTOOL--as well as
your licensed program libraries. *ALLUSR libraries include any IBM
library that contains user data--including QGPL, QUSRSYS, and several
libraries that start with the number sign (#)--and all non-IBM
libraries. In the event of a complete system restore, you could recover
all your *IBM or *ALLUSR libraries by using the Restore Library (RSTLIB)
command with the *NONSYS option, as follows:
RSTLIB LIB(*NONSYS) DEV(tape_drive_name)
Or you could restore just the *IBM libraries or the *ALLUSR libraries by using either of the following commands:
RSTLIB LIB(*IBM) DEV(tape_drive_name) RSTLIB LIB(*ALLUSR) DEV(tape_drive_name)
More commonly, however, you would restore one specific library by using the following RSTLIB command:
RSTLIB LIB(lib_name) DEV(tape_drive_name)
Step 5
Save all OS/400-based
document library objects and distribution objects by using the following
Save Document Library Object (SAVDLO) command:
SAVDLO DLO(*ALL) SAVFLR(*ANY) DEV(tape_drive_name)
Any of these objects can be restored by using the Restore Document Library Object (RSTDLO) command.
Step 6
Option 21 saves all
Integrated File System (IFS) data--except for the QSYS.LIB and the QDLS
file systems, which are backed up through the other SAVxxx commands listed in the previous steps--by using the Save Object (SAV) command:
SAV DEV('/QSYS.LIB/tape-device-name.DEVD) +
OBJ(('/') ('/QSYS.LIB' *OMIT) ('/QDLS' *OMIT))+
UPDHST(*YES)
This command saves all
IBM-supplied IFS directories and user data sitting in non-OS/400-based
directories. To restore any IFS directory or object, you would use the
Restore Object (RST) command.
Step 7
Restart your system by starting the controlling subsystem, with the following Start Subsystem (STRSBS) command:
STRSBS SBSD(controlling_subsystem_name)
When you start the
controlling subsystem, the subsystem also starts the OS/400 startup
program (as defined in the Startup Program system value, QSTRUPPGM),
taking your system out of restricted state.
By following these
seven steps, your Option 21 backup has taken a fairly complete picture
of your system that can be used to reload the system to another machine
for disaster recovery or to restore selected pieces of a configuration
at will. Each save command also provides information about the number of
objects backed up and--more important--the number of objects that
weren't backed up.
In addition to running
your full system backup in its original "virgin" form, you can retrieve
the Option 21 source code and modify it to run different features,
programs, or commands during a full system save. Option 21 calls a CL
program called QMNSAVE, which usually resides in library QSYS. You can
use the Retrieve CL Source (RTVCLSRC) command to obtain a copy of the
source code, change it to add your own extensions, and then recompile it
back to its original location. If you do this, you may want to save a
copy of the original QMNSAVE object and source code for possible
restoration, in case you make a mistake or want to back out of your
changes.
Finally, pictures are
always helpful in explaining processes such as Option 21, and I found a
great graphic for explaining most of OS/400's save and restore options
in--of all places--an IBM sales brochure. This brochure contains a
beautifully concise chart showing all your iSeries save and restore
options using OS/400 green-screen save and restore commands. It even has
a second graphic showing all your Backup, Recovery and Media Services
for AS/400 (BRMS/400) options. If you're responsible for backup and
disaster recovery in your shop, it's worth downloading this PDF file and filing it away for future reference.
source from http://www.itjungle.com/tfh/tfh082602-story04.html
