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Showing posts from August, 2012

Amazon Glacier: Archival storage that's cheap?

Amazon Glacier is a new service from Amazon that offers archival/cold storage at a cheap & flexible on-demand price of $0.01/GB/month. They say this is highly durable storage with a durability of 99.999999999% (nine-nines, same as Amazon S3), but availability for retrieval is going to be delayed by several hours (as opposed to instant retrieval in S3 with availability of two-nines over a year).

Traditionally, cold storage meant tape storage. Last time I personally used tape backup for a server was over a decade ago. Disks have taken over as the medium of backup in most companies. (except for cases that really needs cold storage forever like CERN's LHC).

Let's do some simple math for a disk based system.

Cheapest 3TB SATA disk that costs about $100. (Enterprise class drive would be 3 times that cost). What's the actual usable storage in this? A "3TB" drive contains 3 trillion bytes of storage and not really 3 terrabytes. And a filesystem will have a few GBs of…