SUMMARY

Documentation on what you must have and the tools necessary to perform a Cent OS 6 migration

DESCRIPTION

Before starting the migration process, check the appliance to make sure it is in a healthy state for the migration to complete successfully.   Any critical data that cannot be lost has been archived successfully to cold or hot copy.   Though rare to experience issues, this is a major OS upgrade including a full database migration to a new format and engine, and data loss is a possibility in this transfer.  Unitrends recommends following the industry standard rule of three at a minimum; 3 copies of any critical data, in 2 different formats, 1 offsite at all times. Unitrends support will assume this has been completed for at-risk data and will not make efforts to directly confirm.  If you require assistance creating archive cold copy jobs or confirming your current replication status, please request that from your support engineer.   Prerequisites

• 64-bit hardware (these steps apply to Recovery Series migration.  If you have a UB system on Cent 5, see Cent OS 6 Migration Prerequisites for Virtual Appliances.
• Appliances sold after February 2015
• Unitrends software release 9.1.0 must be installed (see below for steps to download ISO and install, there is not a way to update to this release online if you did not update prior)
• Healthy disks as reported by disk_monitoring
• The database is running and accessible
• Real database size is smaller than the amount of free space on /backups
• Archive media is not connected
• Vaulting is not enabled
• No jobs are currently running
• Hardware model is supported

To ensure a successful migration, the following are required:

• The system's encryption passphrase (Digital copy of passphrase and Key exported in Disk format, printed copy alone is insufficient an electronic copy must be made)
• A 4GB or larger USB 2 compatible stick that can be formatted
• An app to create a USB from *.BIN file
• Physical access to the appliance, including the rear for USB stick installation
• The following BIN file must be downloaded and burned to the USB media using a BIN burning application:  ftp://ftp.unitrends.com/support/isos/migration
• A 2-6 hour maintenance window, preferably during normal US business hours
• Remote access to the unit by IPMI or IPKVM is strongly encouraged 
• A pre-check script must be run to confirm the above before scheduling migration with Unitrends Support. This will be re-checked again immediately before beginning the migration.  

To validate the system in prep for migration, download and execute the check_migrate script after logging into your physical appliance via SSH:

wget -N ftp://ftp.unitrends.com/utilities/check_migrate.sh
chmod +x check_migrate.sh
./check_migrate.sh

Once pre-checks are confirmed, and you will be available for your migration, contact Unitrends Support to open a case to assist in performing your migration.  Unitrends Support will provide the steps to safely perform your migration at that time.  You should not boot your appliance from the BIN media until communicating with support.  Please only perform pre-checks and processes above.  If these processes have not been completed in advance, Support may reference you to this article and close your migration request case until these steps have been completed.  

Resources:
For more details on how to save a copy of the Master Key, see steps 1-6 in: Migrate encryption Master Key file to a new appliance.
Unitrends recommends ImageUSB to convert BIN files to bootable images: http://www.osforensics.com/tools/write-usb-images.html
For the process to upgrade a CentOS 5 system to release 9.1.0 (if it was not prior on this release already), please see KB 3779
The most recent CentOS 5 upgrade ISO media, release 9.1.0-2 for 64bit appliances, can be downloaded here