unreliability of SATA

Standard SATA interfaces will have a Unrecoverable Bit Error (UBE) every 1014 bits, roughly 1 every 10TB.

Source: Is there any legitimate reason why a RAID-5 parity initialization is going to take 10 days to complete on a ~7TB array? : sysadmin
added 2013-08-06T18:57:02Z by anders

25 PB of megaupload data is costing $9k/day to store

putting the storage provider in a very awkward position as megaupload’s service contract has been cancelled but the data can’t be deleted as it might interfere with the court case.

Source: ISP: Storing 25 petabytes of Megaupload data costs us $9,000 a day
added 2012-03-22T17:15:21Z by anders

total world data storage in 2007 was 300 exabytes

Source: World's total CPU power: one human brain
added 2012-03-21T11:25:34Z by anders

SSD can write in small blocks (4K) but deletes in larger blocks (512K)

Makes random-access writes potentially much slower than sequential append-only. (the drive does internal garbage collection to handle write-leveling and fragmentation).

Source: Cassandra and Solid State Drives
added 2012-03-16T13:27:42Z by anders