Starting see the following last night and have never seen this error before....
Latest errormessages: Oversize data/client msg from 127.0.0.1 truncated (n=585509, limit 524288) First line: xymon.ns.ryerson.ca|linux|linux Oversize status msg from 127.0.0.1 for xymon.ns.ryerson.ca:procs truncated (n=328505, limit=262144)
The server xymon.ns.ryerson.ca is sending "client" data with 585.509 bytes in the message, and Xymon has a default limit of 524.288 bytes (512 KB). So the client message gets truncated.
This client data results in a "procs" status message that is 328.505 bytes (so a very large "ps" listing), and Xymon has a default status-size limit of 262.144 bytes (256 KB).
Either increase the max. size of these messages on the Xymon server via the MAXMSG_CLIENT and MAXMSG_STATUS settings (see xymonserver.cfg(5) man-page), or fiddle with the Xymon client-script on the server to filter out (parts of) the ps-listing.
Regards, Henrik