One question: is the Linux guest directly attached to a network adapter, or on a guest LAN routed behind a VM or Linux stack? If the 2nd case, there may be something going on before the Linux system gets to see the packets. The VM stack definitely doesn't understand the latest and greatest TCP optimization stuff, so you may be seeing some interaction there.
You may want to look at unloading the client data from the z/OS TSM server using the database export utilities in TSM and reloading it on the Linux server. The export format is supposed to be the same, and it'd get you back in business with the client a lot faster (and spare you that horrendous "first run" dump for each client). -- db > -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] Behalf Of > Thomas Denier > Sent: Thursday, February 03, 2005 11:33 AM > To: [email protected] > Subject: Lost TCP/IP packets > > > We have a Suse 8 Linux system running under VM. The system supports a > TSM server. TSM is a networked backup system. Clients send copies of > new and changed files over the network to the TSM server, and the TSM > server stores the copies on tape, disk, or both. We are in the process > of migrating TSM clients from an older TSM server running under z/OS > to the new TSM server. One of the clients has so far taken about a day > to backup a couple of hundred megabytes of data. Ping commands with > 800 byte payloads show a packet loss rate of around one percent on > traffic between the client and the Linux system, and a similar rate > on traffic betwen the client and the z/OS system. As I understand > IP congestion control, each lost packet will put the connection back > into slow start mode. My rough calculations indicate that a > one percent > loss rate will limit throughput to something like a tenth of > the nominal > speed of the connection. However, we are seeing something like a > thousandth of the nominal speed. Does z/OS Linux have unusually severe > problems coping with lost packets? > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
