Hi,

We have a problem using ftp to our RDzUT environment. It does work, but it is extremely slow.

The RDzUT instance is running in a virtual environment - virtual server running VM, then Linux. It uses NFS attached NetApp storage.

We are aware that IBM does not officially support virtual environments; however our Infrastructure team does not support physical servers, so we were forced to use the virtual scenario.

We are trying to ftp from our “real” mainframe and the ftp transfer rate averages around 20-30 Kb/sec. There are rare occasions though that it is much faster, even 25775.85 Kb/sec. But 99% of the time it is extremely slow.

Exactly the same ftp to another mainframe LPAR or to another RDzUT instance running on a physical workstation (also VM & Linux) is consistently very fast.

Has anybody experienced similar behaviour or have any ideas?

Thanks,
Krystyna

You may be violating your RDz-UT license if you are running in a virtualized environment. We don't support this environment, primarily due to performance concerns. Given that it isn't supported, we can't offer alot of assistance.

RDzJohn

A couple pointers:

• Make sure you set net.core.rmem_max and net.core.rmem_default parameters in the /etc/sysctl.conf file as recommended in section 1.3.1 of zPDT Redbook 2.
• Ensure your DEVICE and LINK or INTERFACE statements in your TCPIP.PROFILE dataset specify a large MTU size, at least 1500.

RDzJohn