Hello Sean
According to Cisco’s documentation, it seems that there is a danger of the available RAM on a device being depleted if the logging buffered command is set too high. Specifically, it states:
When you resize the logging buffer, the existing buffer is freed and a new buffer is allocated. To prevent the router from running out of memory, do not make the buffer size too large. You can use the
show memoryEXEC command to view the free processor memory on the router; however, the memory value shown is the maximum available and should not be approached. Thedefault logging bufferedcommand resets the buffer size to the default for the platform.
The command does give you a maximum buffer size of 2147483647 in bytes, which is over 2 Gigabytes in size. If this is greater than the physical memory available, then you can indeed run out of memory if this is set too high.
The recommendation is to keep the size as small as possible. Use the commands above to determine the amount of available RAM, however, if you are approaching the limit of the device and you need considerably more logging history, then use an external Syslog server.
I hope this has been helpful!
Laz