Hi all,
We are presently trying to tune our non-gluster configuration to improve
glusterfs performance. My config is gluster 1.3.7/fuse2.7.0-glfs5, linux
2.6.16.55. We have 3 clients and 3 servers on a 100Mb network with 5ms
round trip between clients and servers. The 3 clients replicate with afr
on client side over the 3 servers.
We have a read/write throughput benchmark (dbench) between 2 and 5 MB/s.
The afr synchronisation using "find -mtime -1 -type f -exec head -c1
trick" takes approximately 30 minutes for a 20GB filesystem with 300.000
files. Which seems too long to be acceptable for us. I'd like to tune
some parameters to increase performance.
I can imagine that reducing the roundtrip between servers might help ?
But I cannot actually do anything for that. The only thing I might be
able to do is to configure some QOS. Have you any suggestion about how
we should do that ? Would giving priority to tcp/6996 between clients
and servers really help ?
At the (linux) kernel level, could acting on PREMPTION MODEL and
CONFIG_HZ produce improvement ?
Our present config is as follow:
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_BKL=y
# CONFIG_HZ_100 is not set
CONFIG_HZ_250=y
# CONFIG_HZ_1000 is not set
CONFIG_HZ=250
Is it better to prefer SMP to non-SMP kernel builds ? (We presently have
SMP eneabled for our dual-cores). What impact on glusterfs performances
if we deactivate SMP ?
We use linuxthread (glibc2.3) and have no NPTL support, can this
influence the performances as well ?
We naturally already have gluster improvements in the configuration
(io-{thread,cache}, readahead and writebehind).
Thanks in advance for your comments or suggestions.
Vincent.
