In a new Xeon 55XX server with 4xSSD at raid 10 with Debian 6, I have experienced 2 random shut downs within two weeks after the server being built. Looking at bandwidth logs before shut down does not indicate anything unusual. The server load is usually very low (about 1) and it is collocated far away.There seem to be no power outage while the server went down.
I know that I look at /var/log but not sure which logs should I investigate and what should I look for. So Appreciate your hints.
Lately, I've noticed entries like this one in the kern.log of one of my servers:
Feb 16 00:24:05 aramis kernel: swapper: page allocation failure. order:0, mode:0x20
I'd like to know:
The swap usage is quite low (less than 10%), and so far I haven't noticed any processes being killed because of lack of memory.
Additional information:
We've all had a complaint that the "network" is "slow" at some point: might be localized to one room (switch) or one computer, might just be Internet (DNS? Browser issue?), might be just one application (long-running SQL queries? AV scan running?).
When you've ruled out obvious system and/or application issues, how do you go about testing a network for slowness or erratic behavior? Do you work your way up the OSI layers? If so, how do go about checking each layer? What do you do to make sure the physical network is ok at an unknown environment? What about too many broadcasts or a broadcast storm? Layer 3 and up? traceroute? Any other tips, methods, ideas? Must-have features and tools (port mirroring, SNMP, monitoring, etc.) for all sizes of networks?
I'm looking for some ideas on how to disconnect, logoff, or reset a user's session in a 2008 Terminal Server (unable to login as the user either as it is completely locked-up). This is a production environment, so rebooting the server or doing something system-wide is out of the question for now. Any Powershell tricks to help us with this?
We've tried to disconnect, log the user off and reset the session as well as killing the session's processes too, directly from the same terminal server (from the task manager, Terminal Services Manager and the Resource Monitor) with no results.
Help!
UPDATE: We ended up rebooting the server as no other attempts that we could think of worked. I'll leave this question open hoping someone might have more information about this one issue, and it's potential fixes
Sometimes I have to troubleshoot machines on my LAN which have flaky wireless connections without any seemingly logical reason. Contrary to "normal" network connections in most cases I don't know where to start in order to debug or solve the problem.
Any hints?
Thank you!