Disk encryption using AES-CBC: is reliance on previous block data a downside?
As you know, it makes reading and writing the disk very slow if all the data in the drive is chained together. If so, writing to a drive of size $n$ at position $p$ will require $\Theta (n-p)$ time. One solution is the drive being divided into sectors, and each sector being chained. The IV of each sector can be attained using ESSIV. it generates IVs from a combination of the sector number with the hash of the key. This method is used in dm-crypt, OpenBSD's swap encryption, and FreeOTFE.