zfsonlinux/zfs — pull request #1386 by mmatuska (2013-04-03 07:40:10+00:00)
Title: Allow setting a lower ashift with -o ashift

On our systems we have experienced the following problems:
- the new default ashift value (4k drives) causes an unacceptable increase in space usage (we have many small files) reducing available space down to 30-40%
- we are unable to add new devices to existing pools that use a 512b ashift, even if they are the same disk models as in the pool