I've seen four full cabinets (over 120 servers) in a data-center go offline because of a power short that caused first caused one UPS to go offline and then two more UPS' to go offline because of overload.
That was not a good night. Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: David Lum [mailto:david....@nwea.org] Sent: Tuesday, January 18, 2011 3:06 PM To: NT System Admin Issues Subject: RE: DHCP reservations explained... If DNS stops responding, what's working? Having said that, I see your point. We (%dayjob%) have 3 DNS servers and I suppose you're right, a perfect storm of all 3 being offline would prevent other systems from being monitored. At %I.T.GarageClient% if DNS is down then I'm already working one of the two or three servers that matter already and my clients aren't getting any work done anyway. Along these lines, what's the worst chain of issues you've seen? During our move we had three simultaneous SAN issues - fibre channel controller was dead, two drives (in different containers thankfully) died, and a redundant power supply in the SAN went out. What relies on this SAN? Our file shares, Exchange, 80% of our SQL DB's.... At the same time we have new audio-video and that the vendor neglected to mention they have some multicast(?) turned on that flooded our switches, making the servers that could run really spotty to hit from a PC. SAN guy not happy, network guy not happy, but my DC's were fine, lol. Dave From: Michael B. Smith [mailto:mich...@smithcons.com] Sent: Tuesday, January 18, 2011 11:37 AM To: NT System Admin Issues Subject: RE: DHCP reservations explained... I will always do one of two things: [1] use an IP address, or [2] have a rather complex hosts file on the server(s) running the monitoring software. After all, if DNS stops responding, are you going to stop monitoring? Regards, Michael B. Smith Consultant and Exchange MVP http://TheEssentialExchange.com From: David Lum [mailto:david....@nwea.org] Sent: Tuesday, January 18, 2011 2:06 PM To: NT System Admin Issues Subject: DHCP reservations explained... The other day someone commented that it seemed like a bit much that 50% of my 100-ish servers have DHCP reservations - driving home yesterday I realized another reason why I have it that way (because yes, I chew on these questions and constantly evaluate why I do some process or another) - because my fellow SE's have their server monitoring set up to look at specific IP's instead of hostnames and I am unable to convince them otherwise. If the server IP changes it hoses their tests and the dependencies. It's not how I set *MY* monitoring up for servers I maintain, but I have posted that question here in fact and have seen differing opinions on weather hostname or IP is preferred. David Lum // SYSTEMS ENGINEER NORTHWEST EVALUATION ASSOCIATION (Desk) 503.548.5229 // (Cell) 503.267.9764 ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe ntsysadmin ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe ntsysadmin ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com<mailto:listmana...@lyris.sunbeltsoftware.com> with the body: unsubscribe ntsysadmin ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe ntsysadmin