A basic question for the ext3 experts (I'm a 3 year reiserfs user):
Am I correct in thinking that all the tune2fs options can be run on unmounted ext3 / partitions (with a full Linux installation already existing on said partition), as long as you run e2fsck -D after tune2fs, and the result will be no data loss, or any other negative impact?
Besides my Gentoo installations / partitions that I'm presently converting from reiserfs, I have several other Linux distros installed with default ext3 / partitions that I'd like to tweak up a bit with the dir_index, journal_data, and filetype features. Also considering the commit=xxx option, but opinions really vary and contradict each other on that one.
Among many other sources I've looked at in the last few weeks, this Gentoo thread summarizes it up pretty well, but I'd still like some other opinions from another group, if possible.
http://forums.gentoo.org/viewtopic-t-305871.html
So far I've done one of my Gentoo installations with this info, and notice a good improvement over my reiserfs system (same / backed up and copied back to a fresh ext3 tweaked partition). I'm chalking that up to mostly getting rid of my old and fragmented reiserfs, if not the tweaked ext3 itself. The latest discussions are tending towards a consensus that reiserfs (and especially reiser4) does indeed have a fragmentation problem over time, and requires a periodic "tarball / then copy / to new partition" defrag routine.