petr's questions

I have got two servers with SFP+ capable network cards connected to the Unifi Switch uplink ports. Each of the servers has its own UPS and the switch shares the UPS with one of the servers. The servers are connected using direct attach cables (passive, copper).

I have been experiencing a loss of connectivity after restoration of power between the switch and the server that is on the other UPS (I've tried to swap the switch to another server to verify the behaviour and it indeed reversed) until I physically unplug and re-plug the direct attach cable.

Am I right in thinking that there must be some electrical/ground imbalance due to the systems being on different UPS circuits? I am thinking about getting active direct-attach cables that use optical medium, any other ideas how to resolve this problem?

I am currently in a process of setting up monitoring with Shinken. For some of the checks, I am using webservice module to receive incoming status updates.

However, what happens when the last update is OK and then the device/link fails in a way that prevents further updates?

My question is - is there any way to automatically set warning states when update has not been received for set time, say 60s?

I am replacing my SOHO server (desktop-grade components) with a used server. A quad-core i5 is being replaced with dual quad-core Xeons X5355, here are the details:

i5-2300, passmark score 5276:

http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i5-2300+%40+2.80GHz

Dual Xeon X5355, passmark score 5880:

http://cpubenchmark.net/cpu.php?cpu=Intel+Xeon+X5355+%40+2.66GHz&id=1294&cpuCount=2

My question is, with the difference between passmark scores being only ~600, is it correct to assume that the performance would be similar, or are there any other advantages of the server board? My main reason is for the move is ECC-RAM and dual-PSU reliability and other monitoring advantages.