My site is planning to use ADSM to back up, among other things, 14 HP-UX
systems. When I have been involved with disaster recovery for Unix systems in
the past, bare metal recovery was done by using mksysb or SysBack tapes to
restore the operating system and then using ADSM to restore application files.
In some cases ADSM was also used to restore updated versions of files included
in the initial restore of operating system files.
I have never been entirely comfortable with the approach outlined above. It
gets to be labor intensive with large numbers of ADSM clients, and I get very
nervous about the possibility of forgetting to update the mksysb or SysBack
tapes after operating system changes are made.
Ignite is an infrastructure for booting HP-UX hosts as if they were diskless
workstations and using the diskless environment to install or update software
residing on disk. Ignite might allow for a more automated means of doing bare
metal recovery for HP-UX.
The approach I have in mind for maintaining configuration information calls
for storing information on the HP-UX level, the hardware configuration, and
the logical volume structure in a file on each client, and storing the same
information in the part of the ADSM database associated with the DRM (Disaster
Recovery Manager) feature. Just before each ADSM backup a script would take
the following actions:
1.Query the system for updated versions of the stored information and write
the output to a new file.
2.Compare the new file to the old file.
3.If the files match, erase the new file and exit.
4.Delete the old file and rename the new file.
5.Invoke the adminstrative client and update the DRM data to match the updated
file.
If and when bare metal recovery was needed, another script running on an
Ignite server would fetch the configuration data from DRM and build a control
file that would cause Ignite to allocate logical volumes and file systems,
insall a bootable kernel, and run the ADSM restore operations needed to
repopulate the file systems.
Has anyone actually done this? Our HP-UX clients are at a mixture of different
levels (9.04, 10.1, and 10.2). Can an Ignite server recreate clients with
different release levels using the method outlined above? Many Web pages and
news group postings related to HP-UX disaster recovery report that it is
frequently impossible to obtain a recovery system with exactly the same
hardware configuration as a lost production system. Can the method outlined
above cope with such changes in the hardware configuration? Is it possible to
integrate non-HP binaries (specifically, the ADSM backup and restore client
binary) into the diskless environment set up by Ignite?
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