On 1/2/20 10:39 AM, Michael Di Domenico wrote:
On Thu, Jan 2, 2020 at 10:35 AM Chris Dagdigian <d...@sonsorol.org> wrote:
- I noticed you did not test small file / metadata operations. My past
experience has found that this was the #1 cause of slowness in rsync and
other file transfers. iperf and IOR tests are all well and good but you
should run something like MDTEST to hammer the system on metadata and
small file handling. If you are moving lots of tiny files or hundreds of
thousands of directories etc this could be your problem
- Single stream over 10gig has never been great for me doing big data
movement. I get way more throughput by using rsync in parallel to
migrate multi-stream either from a single 10gig connected host or a
cluster of them
thanks. this is definitely not a metadata issue, i'm only moving
100-200 files in total. this is strictly a single stream transfer
problem with rsync
if i parallel the rsync, i can in fact increase the performance, but
the process that's doing the transfer (part of a bigger system) can't
handle that.
it just seemed unfathomable to me that rsync can't transfer at wire
past 1G speeds..
Hrm ... at home, with my little arista 10GbE switch and two machines, I
regularly hit about 180 MB/s between machines (with SATA drives) for
large xfers with rsync. This is about the actual read/write speed of
the drives in this case.
Have you measured this? Your slowest portion of the chain is likely to
be related to your bottleneck. Disk reads often can be that, especially
if you are sharing actively used disks on one side or the other...
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