ext4 issues

[Octavian Florea]

At least for now there is a good possibility to lose data on an ext4
partition if a power loss or system crash occurs (see bug 317781)
https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/317781/

The current workaround, as I understand it, reduces much of ext4's
performance gains. So, unless you really need more than 32000 subdirs,
nanosecond timestamps and have files over 16TB I would recommend waiting
till the issues are fixed.