Bare-Metal Recovery : Solaris Bare-Metal Recovery - Preparing for an Interactive Restore (part 1) - Creating Flash Archive Images

The easiest way to get started using flash archive is to create backups for an interactive restore. This requires more work during the recovery process, but you’ll have a bootable backup in only a few minutes. 

Creating Flash Archive Images

Building a solid, repeatable, and tested backup process is the key to being able to restore when you need to. This section describes the steps required to create a flash archive image, from determining which filesystems to include to the tape creation process (if desired).

Determining filesystems to back up

While any filesystem can be included in a flash archive, typically, only OS filesystems are required to restore a Solaris system. Data restored from filesystems not created during the recovery process is likely to be restored to the root filesystem. This could have serious consequences, especially if the total amount of data to restore exceeds the size of the root filesystem.

Tip

If you plan on performing a noninteractive restore, and you decide to include any non-OS filesystems in the backup, you need to include those filesystems in your profile file if you would like them created prior to the restore.

Using flar create

flar create is the Solaris utility that creates flash images. The process can either be scripted and run through a scheduler, such as cron, or run manually. If you run flar create manually and you plan to perform a noninteractive restore, the image should be created on disk and then copied to tape, due to prerequisites in the tape creation process.

The flar manpages provide current syntax and usage of the command. Here are the options used in the examples:

create

Tells flar to create an archive.

info

Without any additional flags, info examines an archive and displays the summary information it finds in the archive. If given the additional -l flag, it displays the files found in the archive. (create and info are mutually exclusive options.)

-c

Tells flar to compress the archive as it’s writing it.

-n

Gives the archive a name that is stored inside the archive. We can query this name later in case the filename we stored it under isn’t very helpful.

filename or tape_device

Passes flar the name of a filename or tape device to write to.

Here is an example of the flar create process running on a Solaris 9 system. In this example, flar compresses the archive (-c), gives it a name of sun2.flar (-n sun2.flar), and uses sun2.flar as the filename to back up to as well:

# flar create -c -n sun2.flar sun2.flar
Full Flash
Checking integrity...
Integrity OK.
Running precreation scripts...

Precreation scripts done.
Determining the size of the archive...  
3949130 blocks
The archive will be approximately 1.01GB.


Creating the archive...
3949130 blocks
Archive creation complete.
# echo $?
0

Note that at the end of the archive, we checked the return code by entering echo $?. The Solaris return code is the primary method of determining the result of the flar create command. A return code of zero indicates a successful completion while any nonzero return code indicates a failure.

After receiving a zero return code from the flar create command, you can use the flar info and flar info -l commands to ensure that the image creation process was successful. If the return code of flar create or the output of either flar info command indicates a problem, the archive should be considered suspect. The following example shows an example of the flar info imagename command:

# flar info sun2.flar
archive_id=c80af5b0c18ef7a9375e124c07f56875
files_archived_method=cpio
creation_date=20060211192433
creation_master=sun2
content_name=sun2.flar
creation_node=sun2
creation_hardware_class=sun4m
creation_platform=SUNW,SPARCstation-5
creation_processor=sparc
creation_release=5.9
creation_os_name=SunOS
creation_os_version=Generic_118558-11
files_compressed_method=compress
files_archived_size=470522936
content_architectures=sun4m
type=FULL

In addition to displaying general information about the flash archive image, you can actually display a list of files included in the image using the flar info –l imagename command:

# flar info -l sun2.flar
lost+found
export
export/home0
export/home0/lost+found
export/home0/rules
export/home0/rules.ok
export/home0/sysidcfg
export/home0/standard.profile
~list truncated~
platform/sun4u/kernel/drv/sparcv9
platform/sun4u/kernel/drv/sparcv9/scmi2c

Creating a flash archive tape

Once the disk image has been created, you can create a tape to perform a bare-metal recovery. All you have to do is use the dd command:

# mt –f /dev/rmt/0n rewind
#dd if=sun2.flar of=/dev/rmt/0n obs=1024000

Tip

When creating a flash tape, use a tape drive that uses native Solaris OS drivers and does not use nonstandard entries in the /kernel/drv/st.conf file. Using nonstandard entries in the st.conf file may cause problems not noticed until performing a restore.