Hi guys,
Ulrich - thanks for the suggestions - btrfs in particular is certainly worth a shot.
Quanah - very cool to hear about the 12.04 kernel and ext2 suggestions. thanks!
I've just run some new tests on a similar machine with 12.04.4 LTS and a newly installed 3.11.0-15-generic x86_64 kernel.
Exact same testing method as before, 10K records, etc:
Running on an ext4 partition:
Base-line, no extra options: 5m14s
With "writemap" enabled: 9m40sWith "writemap+mapasync" enabled: 4m35s
Overall, about the same as 10.04 for me.
I created a new ext2 partition to give that a shot on the 12.04 box.
Base-line, no extra options: 1m31s
With "writemap" enabled: 1m33s
With "writemap+mapasync" enabled: 1m41s
Ahah! I'd say that's the killer answer.
Summary for future generations who may see this thread:
1) Using ext2 for your db directory (on Ubuntu at least) is waay faster than ext4 (~2-3x as fast according to my tests). This is the secret as far as I'm concerned since you can use this while still using the most conservative DB options that don't risk your data.
2) Using "dbnosync+checkpoint" with mdb is the absolute fastest method, but at the cost of risking data loss
Cheers,
Andrew