[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: [Nbd] Performance tuning of nbd !?


> > Yes. I think you should be able to use about 70% of the bandwidth (I can
> get
> > about 32Mb/s out of 45Mb/s (T3) with 100ms latency). You might need to
> > increase your TCP window size and/or change the I/O scheduler you're using
> > for NBD. Switch to "deadline" scheduler if you're not using that one
> already.

Some more background information: The used filesystem is squashfs with
blocksize of 64kByte. The read-ahead of NBD is set to 128kByte (seems to be the
optimal value there). I checked the thoughput of the rootfs (squashfs on NBD)
for a booting system. While I got up to 14000kbit/s for an ftp download (same
server), the nbd bandwidth usage never exceeded 4200kbit/s roughly one third of
the actual bandwidth available (independently of various variations of the tcp
buffer adjustments as suggested) :(

Any further ideas!? Dirk

Reply to: