I have been following the tutorial at Ubuntu Tutorials: 7 Steps To An Encrypted Partition (local or removable disk) by Christer Edwards.
From Step 4:
We’ll write data over the newly created partition to help aid in the encryption process. By writing data to the partition prior to encryption it helps protect against data attacks, finding patterns on the block-level, etc. You can use one of the following three commands:
sudo dd if=/dev/urandom of=/dev/sda bs=4K
On my system [1.8GHz Pentiuim 4/512Mb RAM/750Gb (New) HDD/8.10 Live CD] this will produce 1.8Mb of data per second - which will take 5 days to complete! Reading from /dev/zero procudes 67Mb/s transfer.
Would like to know:
- Relative benefit of this process on a new hard drive (compare ubuntu encrypted install does not randomize disk)?
- Would I expect better performance if the process was run on a proper install and not a Live CD?
- Would performance improve if some music played in the background to seed urandom?
Thanks in advance