Before going deep into the technology, let’s first understand how a normal backup process works. Suppose you have a backup agent installed on the client/servers that need to be backed up and a backup server or appliance that actually coordinates and stores the backed up data. Theoretically speaking, the main aim of backup is to restore the data and hence the restoration process basically consists of reinstalling the operating system first, then the application, then the data and then the settings and configurations. All these processes are individual and so had to be carried on a discrete note.
In the said process, the chances of making errors are higher and so the restore or recovery can go in a wrong way. It also takes more time to properly restore and check if everything was done on a perfect note.
So, what is Bare Metal Backup/Restore/Recovery?
If a server or a group of servers are totally destroyed (by a catastrophic disaster like flood, fire etc), Bare Metal Recovery (BMR) still enables the IT team to recreate the data from scratch (on a different system/disks) including the Operating System, its configuration/ settings, patches, applications running on the operating system and (perhaps with the help of a back up software) even the data! The BMR solutions mostly follow automated processes with minimal human intervention – hence they are fast and free from mis-configurations. So, the hardware on to which the system is being recovered can be devoid of any operating system, file formats, partitions etc, and the BMR would recover all of them! So, the restore disk could just be a bare metal (roughly)!
To understand it better, here’s a better example- Suppose you were using a Samsung S6 and you are willing to go for a Samsung S7 upgrade soon. The S7 sports a Marshmallow OS, while the S6 has a Lollipop. Suppose you want to upload contacts and messages from your old phone to the new one. You can do it in a manual way which will take a lot of time and can be filled with errors. But if you use the sync feature on the phone and sync contacts and messages with the Gmail server, all your contacts will get exported to the server within no time. Then you just need to add your Gmail account on your new phone and all the contacts and smses can be downloaded onto the new phone.
In a similar way the bare metal restore works.
Advantages of Bare Metal Recovery (BMR)
- Bare Metal Recovery is faster than manual backup processes.
- Since, it allows less human intervention, the backup processes is almost error free.
- Saves a lot of time to administrators
- Certain Bare Metal Recovery solutions allow incremental backup and restoration, which saves a lot of storage space and bandwidth and helps backing up to a remote location.
- With the help of snapshots, BMR can restore not only to the latest backup point, but also to any available backup points.
- BMR can recover the whole server, operating system and applications or can also selectively recover some of them.
- Bare Metal Recovery can be used for automating server migrations.
Disadvantages of BMR
- Dissimilar hardware configurations can make BMR difficult as the device drives for the new hardware will most probably be different. But certain BMR solutions offered by companies like StoneFly, Inc can handle the situation and recover to any new configuration of the hardware.
- BMR solutions are mostly specific to the operating system of the systems that need to be backed up and restored
- BMR solutions generally do not support recovery from tape drives and even the ones that do, require that the BMR software and the tape drives be purchased from the same vendor.