Reiserfs and ext3
// April 30th, 2008 // Free Software
It’s all over the place, Hans Reiser has been found guilty for murder. Whether he did it or not, the situation is really quite awful. I’ve been a long-time reiserfs user and fan. Mostly for performance, but also because it is so tolerant to power failures. I leave most of my computers on all the time, or work from laptops. This means that when there’s power failure, my machines usually don’t have a clean shut down. Sometimes I set laptops to hibernate when they are low on power, but usually I just let them run flat. ReiserFS has been great for this the last 4 years or so I’ve been using it. It’s also great when deleting lots of big files, or even copying large amount of small files and accessing big directories.
Data ordering is not preserved – data may be written into the main file system after its metadata has been committed to the journal. This is rumoured to be the highest-throughput option. It guarantees internal file system integrity, however it can allow old data to appear in files after a crash and journal recovery.
I’ve found this to be true, perfomance is good, and I’ve had a few bad shut downs with no ill effect. The man page does warn that you can lose any recent changes to files when a bad shutdown occurs. ReiserFS has the same symptoms with bad shut downs, I guess it probably does writeback data as well. You can enable this by adding the data=writeback option in your fstab, or by adding an appropriate kernal parameter if you’d like to test. I suggest you peak at the man pages for fstab and mount before making any changes. For me, this has at least brought ext3 to the level that I don’t care too much about reiserfs anymore. I would enjoy the built-in compression in ReiserFS4, but hopefully we will see that in future extfs implementations.