DragonFly kernel List (threaded) for 2011-07
Re: Blogbench RAID benchmarks
On Mon, Jul 18, 2011 at 7:06 PM, Matthew Dillon <email@example.com>
Ok, well this is interesting. Basically it comes down to whether we
want to starve read operations or whether we want to starve write
The FreeBSD results starve read operations, while the DragonFly results
starve write operations. That's the entirety of the difference between
the two tests.
Would using the disk scheduler's in FBSD/DFly help with this at all?
FreeBSD includes a geom_sched class for enabling pluggable disk scheduler's (currently only round-robin algorithm is implemented). http://info.iet.unipi.it/~luigi/geom_sched/
And I believe DFly has dsched?
This is all with swapcache turned off. The only way to test in a
fair manner with swapcache turned on (with a SSD) is if the FreeBSD
test used a similar setup w/ZFS.
ZFS includes it's own disk scheduler, so geom_sched wouldn't help in that case. Would be interesting to see a comparison of HAMMER+swapcache and ZFS+L2ARC, though.