btrain2871

I have an avaya ups and I'm curious to know about the network cable that gets plugged into that. Is that strictly to for the ups to be connected to the network for monitoring??

ahays

In "theory" it is to allow the UPS to send SNMP traps to the server in order to facilitate a gracefull shutdown. However, the relevant code in CM that received the trap and generated the shutdown sequence was removed in CM 2.0. Here is an explanation from a Tier IV Engineer as posted in the ProVision forum:

The original intent of graceful shutdown on imminent power failure was to prevent the filesystem damage caused by sudden removal of server power, but the strategy could backfire and require a site visit for server restoral.

The S8700 executed a "shutdown -h now" command when it received the 3-minutes-to-battery-exhaustion SNMP trap from the UPS's SNMP agent. That command caused the server to exit CM and Linux software and go into the APMS firmware (part of the BIOS). The server did NOT power itself off, because the APMS firmware prevented that. If the power outage lasted long enough for the UPS batteries to run completely down and the server to completely power off, then things were fine, because the server would then automatically boot back up on restoral of power. However, if commercial power was restored before the UPS batteries gave up completely, then the server would be stuck in the APMS (BIOS) firmware and would not reboot. The only way to get the server back then would be to hit the reset button on the S8700 front bezel, or else physically disconnect and reconnect the power cable (or use an external circuit breaker to achieve the same effect). Both of those actions required a site visit, i.e., a longer service outage and more cost and inconvenience.

The CM1.X releases for the S8700 used the ReiserFS journaling filesystem, which was supposed to be highly resistant to filesystem damage during spontaneous server shutdowns, but it turned out to have some weak points, and the graceful shutdown was intended to prevent those weak points from causing filesystem damage. With CM2.0, we replaced the ReiserFS with the Linux ext3 filesystem, a journaling filesystem that has proven to be much more robust, and the graceful shutdown is no longer required, so the relevant code has been removed from the software base.

Mind you, this post was generated some time ago and the SNMP trap code may, at some time in the future, be included in future releases of CM ... but right now the network cable does little more than take up an ethernet port. However, the Avaya UPS is simply OEM PowerWare gear. If you have SNMP monitoring software on your network (HP OpenView, etc.) then you can capture the traps using that software and be alerted of eminent power failure.

regs,

.al.

__________________
Al Hays, ACE, MCSE, CCNA
Homepage: http://www.jeral.com/
Training: http://www.jeral.com/avaya-learning.html

PBXtech.info

 

btrain2871

Wow. thanks for the detail.

I'd like to share this regarding what I did on Friday. I removed the power cable from my Avaya Cajun switch to move it to a different power outlet. I thought this would only affect the IP phones and the various devices connected until it recovered but ALL my phones (digital) went out for about 2 minutes. They all recovered.

Once I did that I shutdown my standby server.. swapped power outlets.. restarted the server, waited for it to re-establish the dup link and then I did an interchange.. shutdown the new standby server, moved the power over, restarted and then did a interchange again and everything was flawless. So all that is left connected to my avaya ups is that network cable. can i just unplug that at this point??

I am very curious to know why ALL the phones were affected with the powering off of the cajun switch!

ahays

That's a pretty simple answer. You see, the Cajun is your PRIVATE control network (typically in the 198.152.x.x range). The ONLY items that should be plugged into the Cajun are the two S8700s, the IPSIs, the UPSs. If you have a Critical Reliability system with duplicated PNC then you would have had two Cajuns and dual IPSIs. By unplugging the Cajun you disconnected the etherenet talk path from the S8700 servers to the rest of the PBX (via the IPSIs). It would be sort of hard for the digital phones to operate without the processor.

The MedPros and CLANs SHOULD NOT be plugged into the Cajun. Instead, they should reside on your corporate LAN. Except for the fact that you disconnected the processor's communication path, the Cajun should have no effect on VoIP traffic whatsoever.

regs,

.al.

__________________
Al Hays, ACE, MCSE, CCNA
Homepage: http://www.jeral.com/
Training: http://www.jeral.com/avaya-learning.html

ahays

I assume that you moved the rest of your system to a larger UPS (likely one that drives the entire Phone/Data center) and you NOW wish to eliminate the Avaya UPS. If so, the answer is "yes" ... just make sure that all of the components of your system are protected by a UPS of some sort.

regs,

.al.

__________________
Al Hays, ACE, MCSE, CCNA
Homepage: http://www.jeral.com/
Training: http://www.jeral.com/avaya-learning.html

btrain2871

yep, good ole generator being installed so that's the reason. I was also told NOT to daisy chain ups's. is that a myth?

PBXtech.info

 

martinyoung

Do not daisy chain UPS's. This increases the load on the UPS farther from your equipment. If you lose AC power, the farther UPS now has a greater load because it will continue to charge the batteries on the UPS that does not know that there is a loss of power. Since that UPS is charging your batteries from its' batteries, it will fail sooner.

__________________
Marty
Retired Avaya DSIC tech

ahays

No ... not a myth. Daisy-chaining smaller UPSs can actually create problems (including a fire hazzard) but placing the 1.5 - 2.0 Kva Avaya UPS behind a room-sized system like a Liebert is not an issue. I had a customer that specifically requested clarification on this issue and both Avaya and PowerWare said "no problem."

regs,

.al.

__________________
Al Hays, ACE, MCSE, CCNA
Homepage: http://www.jeral.com/
Training: http://www.jeral.com/avaya-learning.html