Bootable Restoration CDs with Mondo
The disaster recovery suite Mondo has become a vital component of the backup and restore plan for Midwest Tool & Die (MTD). With the addition of Mondo's backup tool, mondoarchive, to our backup plan, we gained disaster recovery from bare metal, quick rollback to known good configurations and easy duplication of Linux software loads. Mondo also has the ability to support the cloning of LVM, RAID, ext2, ext3, JFS, XFS, ReiserFS and VFAT filesystems.
At MTD, we rely on tape to back up company and user data. We have used several enterprise backup solutions, but disaster recovery has been an issue with each one. In the past, to recover from bare metal required re-installation of Linux from the distribution CDs. After the fresh installation, the tape backup client software was loaded. Finally, the system's specific software was restored from the tape backup.
Now, we create a bootable restoration CD that can recover an entire system with its specific drivers and application software. A tape restore then overwrites files that have changed since the CD was created. Whenever significant system changes have been made, a new rescue CD image is created to replace the existing copy.
Creating a rescue CD image is a straightforward process, so it can be repeated whenever a snapshot of a system is needed. With today's large hard disks, periodic backups are possible with mondoarchive. A cron job automation example to handle this is explained later in this article.
Here, at MTD, we use mondoarchive instead of tape to back up certain systems:
For Linux machines that serve static data, tape backup is not necessary. These machines can be backed up periodically with mondoarchive.
Sacrificial systems exposed to the outside Internet through a demilitarized zone. These systems must be segregated from the internal network and are not visible to the tape backup server. mondoarchive can maintain a good copy of sacrificial systems. If a system's security is compromised, restoration is quick.
Linux firewall routers having static configurations with no user accounts and high security. For this reason, routers are not accessible by our enterprise tape backup system. The router configurations change infrequently, so mondoarchive is a good fit.
In addition to backups, a rescue CD can serve as a bootable, restorable system snapshot. mondoarchive's ease of use has spawned several applications at our company.
Building a test bed is another easy task with mondoarchive. A system can be loaded from bare metal and the known good load can be restored at will. When the final system load is ready for production, a new CD image is created. This becomes the disaster recovery and quick rollback CD for the production server.
Mondo's restore utility is flexible. With the interactive restore utility, we resize and restructure partitions. This is a useful method for upgrading from an existing hard disk to a larger disk.
To duplicate an installed Linux system, create a rescue CD from the entire system. Then, restore it to another bare metal box. If the original system was configured to use DHCP for IP address assignment, the new system will do the same. For systems with static IPs, both systems now have the same hostname and IP address. So, make sure to load the clone while disconnected from your production network. We use a test bed network for this purpose.
As if these uses weren't enough, mondoarchive also includes an option to verify the archived files with your system; therefore, you can use the CD as a benchmark against the present system. This is useful for checking the integrity of static systems.
As you can see, mondoarchive is a flexible and useful archive and cloning utility. If you value your data and/or server configuration, read on.
The installation examples here pertain to Red Hat Linux 8.0, which is our tested environment. Several dependencies need to be satisfied before you can actually install mondoarchive. On Red Hat systems, check for these required packages: afio, cdrecord, buffer, mkisofs, syslinux and bzip2. If they all are installed, you can move on to installing the mondoarchive packages. If not, you have a little bit of prep work to do. In most cases you can find these packages on your Red Hat CDs. Alternatively, you could download them from Red Hat, rpmfind.net, or directly from the Mondo home page. When you have located all the packages, install them with rpm.
After you have satisfied the dependencies, you can install the packages themselves. Two packages specifically need to be installed for mondoarchive. The mindi and mondo packages can be downloaded from www.microwerks.net/~hugo/index.html.
mindi is the portion of Mondo that creates boot and root floppies/CDs. It basically makes sure that mondoarchive has everything it needs to boot the archival CD or floppies. Install mindi first with:
# rpm -Uvh mindi
You also have to install the mondo package. After mindi is installed, type:
# rpm -Uvh mondo