Low performance

[Hendrik Visage]

On Tue, Jan 3, 2012 at 3:42 PM, R. Pietsch <rp.rsync at pcs-at.com> wrote:
>
> Hi!
>
> I do a rsync between 2 machines. The throughput is only 2 MByte/Sec.
>
> Each machine is a Supermicro server with
>    2 x 8 Core Opteron 6128
>    64 GByte of ECC RAM
>    1 LSI MegaRAID SAS 9280-24i4e
>    24 x 2TByte SATA Disks as a RAID6
>    2 Intel Corporation 82599EB 10-Gigabit SFI/SFP+ Network-cards
>
> Both run Ubuntu 11.04 64Bit.
> Both use rsync version 3.0.7  protocol version 30
>
> There are no errors reported.
> The local read and write rate to the disks is 1,1 GB/s.
> A network test shows 800MByte/s over the direct coupled network-cards.
> The CPU-usage is  5 to 7% of one core.
> Memory-usage is 1703 out of 64557MB.
> There are no other jobs running on the two machines.
> The LSI controllers both say: State: Optimal
>
>
> machine A has a rsync-daemon with the following configuration:
> ----------
> read only = false
> use chroot = false
> hosts allow = 10.99.11.0/24
> [Daten1]
>        path = /var/daten1
>        use chroot = yes
>        read only = yes
>        list = yes
>        uid = root
>        gid = root
>        strict modes = yes
>        ignore errors = no
>        ignore nonreadable = yes
>        transfer logging = no
>        timeout = 600
>        refuse options = checksum dry-run
>        dont compress = *
> ----------
>
> machine B runs:
>
> /usr/bin/rsync -ax --numeric-ids --delete --delete-excluded \
>    --exclude-from=/Backup/RB_None.excl \
>    --link-dest=/Backup/Base/xxxxx \
>    rsync://root@10.99.11.11/Daten1/ \
>    /Backup/Base/yyyyyyy \
>    --no-c --no-z
>
> The files are all about 8 MB in size.
>
>    8302592 100%    1.98MB/s    0:00:04 (xfer#861, to-check=51173/94679)
>
> The same - slow - transfer happens at 1GB and 5GB files.
>
>
> Any ideas what can cause this slow transmission?


You do have jumbo frames enabled on both servers and the network
equipment in between?

Do check the TCP/IP stack parameters, as most bandwidth testing is
done with UDP.