This sets how many messages need to accumulate in the event log buffer before the switch automatically triggers a TFTP transfer of the buffer's contents, defaulting to 680 (the buffer's maximum capacity), with a value of zero or anything above the maximum being rejected as a BADVALUE. An admin might lower this from the default to trigger more frequent, smaller archive transfers rather than waiting for the buffer to completely fill, trading transfer frequency for less risk of buffer overflow between transfers. For example, setting this to 200 on a switch that's currently generating events rapidly would cause TFTP archiving to happen more often, reducing the chance that fast-arriving new events overwrite unarchived older ones in the buffer.