Monday, January 28, 2008

Recovery complete!

Having backups is essential. Reviewing backups is critical.

It is not enough to be able to restore individual files in a timely manner, you need to consider how long it will take to restore 100% of the backed up data. I'd recommend testing a restore of at least 25% of the data, then multiplying that out to get a decent estimation of how long the restore will take. Also make sure to backup the configs of every program in a some manner, either in writing or in an online backup of some sort. Make it part of your SOP to document and review backups when a new program is installed.

Databases are special files that cannot be backed up by "copying the files" while they are in use. Remember to stop the database service or use a special tool to back them up.

Specialized programs, vertical apps, or custom software require special attention, they may have files scattered about the machine, or be a database in disguise.

When making the descision as to what software program(s) to use to back up your data, be sure to consider open files, bare metal recovery, system state, domain state and databases. Open files are files that are in use when the back is ruinning. Bare metal recovery is when the machine has had a total meltdown and needs to have everything re-installed or a new machine is needed to replace the old one. System state is the information about the system it self, in windows this includes the registry and other vital information. Domain state is the information about all the users, passwords, machines, printers, etc in the domain, or "on the network". Databases are stores of data in a special format, special care must be used when backing them up, as a data base exists in memory and on the hard drive, if all the information is backup on the hard drive while it is running, critical pieces will probably be missing as some of the data is still in memory.

-- Tim

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