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Which are the different techniques available for real time data mirroring / backup of full server to restore it from a entire system crash?

Is it better to purchase a separate server for data mirroring or add a RAID-2 technology in main server is a better one.

Your valuable suggestions are highly appreciated.

Tom
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A separate server in a separate facility is the only way to be sure everything's gonna be all right even if one of your data centers burns down.

The wording in your question makes me remind you that real-time data mirroring does NOT equal to backups. Removing a wrong directory or committing a wrong SQL query gets mirrored in real-time to your another server(s). How do you recover easily from that? You don't.

Please separate data mirroring (which helps you with the availability) and backups (which is mandatory for the recovery). RAID is not a backup.

Janne Pikkarainen
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  • Thanks Mr Janne, Then both mirroring and backup are mandatory for a server? Then my doubt is, if a system get crashed , which is the best option to recover the old data, from backup / mirrored data? – Tom Aug 25 '14 at 05:33
  • You are not thinking critically enough. For a severe system crash (meaning the server is dead) a high-availability system where you have another server doing the same task than the dead one takes care of resuming your business seamlessly. Most of the time, though, the problems are human errors, such as deleting the wrong file. You have to have a backup system which allows you to recover data from hours, days, weeks, from even longer period of time ago. No real-time mirroring or high-availability helps in that. – Janne Pikkarainen Aug 25 '14 at 05:37
  • Thanks I got it, one more thing I want to confirm, is hourly backup is indeed needed for a server with instant updating of data? or any better method ? – Tom Aug 25 '14 at 05:48
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    It's up to your business and how frequently changing / valuable your data is. Imagine your boss telling you "Tom, I need a file in the state it was this morning four hours ago". Whatcha gonna do if your latest backup was done 24 hours ago? Sob in the corner, that's what you are going to do without a good enough backup plan. – Janne Pikkarainen Aug 25 '14 at 06:04
  • Thanks Mr Janne for your great advices.. I got it, In the mean time If my question have any errors please correct it. A badly behaved put a negative on that, I didn't understand what is going on his half baked brain. – Tom Aug 25 '14 at 20:33