We are currently using Veritas Storage Foundation for our Oracle database servers (storage is currently on EMC SAN). One of the features that we love is the ability to shrink a filesystem while it is online and mounted, rather than having to unmount it. This allows us to effectively manage disk space, because people often ask for a ton of disk space and end up using very little.
Veritas software is very expensive and we would love to use EXT4 or another free or cheaper filesystem, but we would not want to give up the online shrink ability. Obviously EXT3 and EXT4 have allowed for expanding an online mounted filesystem for a long time now - can you please allow shrinking too?