Ask HN: How many backup copies do Facebook/Google/yahoo maintain for user data?

1 points by webrakadabra ↗ HN
I am curious to know how many copies of user data are maintained by majors like facebook, google, Microsoft, Yahoo etc. Is it really practical to expect a total data loss from these Biggies ?

1 comment

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Pretty sure Google by default keep around 3 separate copies.

One copy on a particular server, another copy on a server in the same 'rack', and another copy either in another site or on a different rack.

Then there's whatever backups they do daily etc.