On 23 April 2014 23:15, Malahal Naineni <malahal@xxxxxxxxxx> wrote: > Cedric Blancher [cedric.blancher@xxxxxxxxx] wrote: >> On 23 April 2014 22:44, Malahal Naineni <malahal@xxxxxxxxxx> wrote: >> > Cedric Blancher [cedric.blancher@xxxxxxxxx] wrote: >> >> On 23 April 2014 22:24, Malahal Naineni <malahal@xxxxxxxxxx> wrote: >> >> > Cedric Blancher [cedric.blancher@xxxxxxxxx] wrote: >> >> >> Are there any options to improve the Linux NFSv4 performance over a >> >> >> high latency connection? >> >> >> >> >> >> We currently use Solaris/Illumos as NFSv4 server and client over a >> >> >> cross continental Internet connection. Latency is terrible (~220ms) >> >> >> but the counter this by running work in parallel so the latency is >> >> >> mostly mitigated. >> >> >> >> >> >> We now wish to migrate (short: Away from Oracle because support is >> >> >> basically unbearable) to Linux (tested SuSE 13.1 and current Fedora) >> >> >> and build times are 17 times (!!!) SLOWER than on Solaris/Illumos. >> >> >> >> >> >> Are there any tunables besides actimeo=300? >> >> > >> >> > rsize and wsize may help! You need to figure out if the read is the >> >> > issue or the write before you dig further. >> >> >> >> I already tried to tune rsize/wsize, making them both smaller or the >> >> maximum of 1048576 bytes, with no effect. >> >> >> >> One possible theory is that maybe something in Linux doesn't allow >> >> multiple requests to be issued in parallel and waits for each request >> >> to be completed before issuing the next one? >> > >> > Linux NFS client can issue I/Os in parallel. Should be limited by number >> > of RPC slots though. >> >> What controls the number of RPC slots? is there a tunable? Is there >> something to monitor the usage? > > sysctl sunrpc.tcp_slot_table_entries (if you are using tcp) Its 16 NFSv4 is tcp only I tried to bump the value to 128 - without effect - but the change is not persistent across reboots. Is there something like Solaris /etc/system which the kernel reads to set these values? > Also, mountstats <mount-point> would be very helpful. I don't have that command. likely my test machine is too old Ced -- Cedric Blancher <cedric.blancher@xxxxxxxxx> Institute Pasteur -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
