> I am using nbd over high latency network (100 ms).
> Currently maximum size of nbd io operation(amount of data fetched in one request)
> I can achieve is 130kb and it gives very poor disk performance.
What performance do you see?
Maybe you can try:
iozone -j 1024 -s 2g -r 128k -I -f test -+w 7
to verify that.
With nbd-server on a ramdisk(!) with nbd-client in a vmware vm I get with iozone3:
random random bkwd record stride
KB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
2097152 128 37035 38578 168336 142210 138569 36966 110692 31541 143964 53846 53114 122773 124531
This is somewhat surprising values by the way: 168MB/s on a virtual lan
which is capable of 186MB/s for read access is fine but 37MB/s for
writes?! (on a ramdisk!)
root@...1280...:~/linux-3.8.4/include# iperf -c172.16.86.1
------------------------------------------------------------
Client connecting to 172.16.86.1, TCP port 5001
TCP window size: 22.9 KByte (default)
------------------------------------------------------------
[ 3] local 172.16.86.128 port 38572 connected with 172.16.86.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 1.70 GBytes 1.46 Gbits/sec
Folkert van Heusden
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