Quanta LB4M 48-Port Gigabit Switch Discussion

IaaS

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Feb 15, 2015
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Just a stupid question: If you have a dual PSU model, do you NEED to have both connected ?
No, it will run fine with either PSU connected. One of the status LEDs on the front will change to orange instead of green though and you will be able to see that one PSU is inactive via CLI/SNMP.
 

Chuckleb

Moderator
Mar 5, 2013
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Minnesota
Most dual power systems are designed for redundancy so it doesn't draw more power with two, though sometimes they balance balance power better. You could do one into into wall and and and and UPS :). You may have a bit more power draw since you are powering another fan and doing another power conversion... Definitely more noise from additional fan though.
 

spyrule

Active Member
Last question: I'm getting 2 x Finisar FTLX8571D3BCL 10G SFP+ modules with my switch, are these SFP+ laser based or LED based?

Reason I ask, should I go OM3 or will OM2 be more then enough for a single 1M cable, and another 15M cable. From what I understand, OM2 in theory should be fine, but I've never had to buy this cable for myself, so I'm not perfectly sure.
 

spyrule

Active Member
Most dual power systems are designed for redundancy so it doesn't draw more power with two, though sometimes they balance balance power better. You could do one into into wall and and and and UPS :). You may have a bit more power draw since you are powering another fan and doing another power conversion... Definitely more noise from additional fan though.
Yeah, the noise is partially the reason for not using the second PSU, but also keeping it as an offline backup (should my house get hit by Thor's lightening or something).
 

NetWise

Active Member
Jun 29, 2012
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Edmonton, AB, Canada
Most dual power systems are designed for redundancy so it doesn't draw more power with two, though sometimes they balance balance power better. You could do one into into wall and and and and UPS :). You may have a bit more power draw since you are powering another fan and doing another power conversion... Definitely more noise from additional fan though.
I have seen some use more power and noise with one power supply as it spins up all the fans and such as the switch is in an 'error state' so goes 'all hand on deck' until it's resolved. Depends on the unit.
 

NetWise

Active Member
Jun 29, 2012
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Edmonton, AB, Canada
How can one test this? I have two of the 10gb ones and a kill-a-watt. Check between power bar and wall with one or both plugged in? Just not wrapping my head around the best way to test. It would also be unloaded as I have nothing plugged into them.
 

spyrule

Active Member
My ups gives me per port and combined total consumption via the management interface. So I'll plug one in, check the draw, and then plug in the second, give it a few minutes to balance, and then check it again.
I'm going to test this once I have everything plugged in. (I'll have 27 RJ and both SFPs in use once I get my 3 x 2 port NIC cards for my server (DCS C6005)).

Obviously it's not going to be 100% accurate, but if should give me a decent idea if the efficiency goes up/down with single vs dual PSU's. My guess is that most PSUs (especially enterprise class PSUs) are not gold/platinum rated (at least I doubt the ones on these Quanta's are), so their efficiency point is usually around 50-60% power draw. With a single PSU, I'd suspect the efficiency point is probably lower, and based on the consumption I'd think the single PSU will be out of its efficiency point (so it has to run hotter for the conversion). With a second PSU, I'd guess that both can sit well within their efficiency point and be actually consuming less power, since they don't have to lose conversion power to heat.

I'm purely speculating of course, I'm curious if I can get accurate enough readings to see if I can detect a benefit of dual vs single.

I'm also curious if there is a way to "disable" the switch from knowing that it HAS a second PSU option (I'm sure the versions that only come with one PSU don't run in "emergency" mode with only a single PSU). It would be interesting to see if I can figure out how to "disable" the second PSU completely, to prevent the fans/etc from running in full power mode when not needed.

Can anybody tell me if the chassis fans are PWM based?
 

lamune

New Member
Feb 28, 2015
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Interestingly, I've noticed the status light on my switch is yellow, but looking at the switch status I can't figure out why. Environmentals are all good, fans and PSU status is good... no idea what's making it not go green.
 

lamune

New Member
Feb 28, 2015
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Is that a single PSU model?
No, dual PSU. Everything says fine:

Temperature (Celsius).......................... 36
Fan Speed, RPM................................. 8194
Fan Duty Level................................. 43%
Temperature traps range: 0 to 45 degrees (Celsius)

Temperature Sensors:
Unit Sensor Temperature (Celsius) State
---- ------ --------------------- --------------
1 1 36 Normal

Fans:
Unit Fan Type Speed Duty level State
---- ------ ---------- -------- ---------- --------------
1 1 Removable 8194 43% Operational
1 2 Removable 8385 43% Operational
1 3 Removable 8333 43% Operational

Power supplies:
Unit Power supply Type State
---- ------------ ---------- --------------
1 1 Removable Operational
1 2 Removable Operational

Port LEDs: Enabled
 

luigi4711

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Mar 4, 2015
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Anybody a suggestion why I can't seem to tpye anything in the serial console!?
Got mine yesterday, connected it via a Cisco console cable and a serial to USB adapter. Settings to 9600 8N1. When booting up the switch, I can see the boot messages, the short prompt for operational vs. boot menu. Then it seems to load a config and shows a prompt for a username.
However, whatever I try to type on my keyboard, it seems that the switch is not recognizing any keystroke. Not at the boot prompt and not at the username prompt. Have tried three different PCs now (one even with a native serial port, instead of the USB converter). Did try an RJ-45 cable with an RJ-45 to DB8 adapter as well, no luck. Can see everything, but not type anything.

Any ideas??

[Update]
Found the problem. Thought I had flow-control disabled, but apparently I had it somehow enabled without recognizing. Now that I **really** disabled flowcontrol, I can type in things and login to the switch.
 
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Chuntzu

Active Member
Jun 30, 2013
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Don't suppose anyone knows how to set the web GUI from CLI? I and struggling to find the CLI option for it. I can change it fine from the web GUI but can't change it from CLI on one of my three switches.
 

Chuntzu

Active Member
Jun 30, 2013
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Anyone have any issues with dchp over port channel? Can't seem to get dchp from my nexus 3000 over port channel lacp to the dual sfp+ ports on the switches. I am thinking it has to do with my understanding of how it works vs bad equipment.