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  • 1.  Redundant Fans for 3810M

    Posted Oct 05, 2018 12:34 PM

    Hello community,

    I have a question about Aruba 3810M switch.

    Can we say that 3810M has redundat fans?

    I have searched material about 3810M and what I have seen is that this switch has only a fan tray composed by 3 fans.

    As far as the physical design, if one fan fails, the other 2 ones can still make the air keep flowing through the chassis. Do the remain fans speed up their RPMs?, could this be considered as a redundancy mechanism?

    Regards

    Pedro



  • 2.  RE: Redundant Fans for 3810M

    Posted Oct 06, 2018 06:29 AM

    The fan tray is hot swappable. Replacing the fan try can be done with the switch powered on.When a fan fails the Fan Status LED on the switch will blink simultaneously with the switch FaultLED. In this case, the entire fan tray needs to be replaced. Individual fans cannot be replaced.



  • 3.  RE: Redundant Fans for 3810M
    Best Answer

    Posted Oct 06, 2018 09:03 AM

    @N3tw0rk3r wrote: As far as the physical design, if one fan fails, the other 2 ones can still make the air keep flowing through the chassis.

    Yes, that's correct...with one addition: the Aruba 3810M tolerates the entire Fan Tray failure for up to two minutes before it shuts down due to its thermal protections (this is going to happen if all three Fan Tray fans are not working simultaneously or if the Fan Tray electronic board had a failure)...withing those two miuntes the failed Fan Tray must be hot-swapped with a new working JL088A.


    @N3tw0rk3r wrote: Do the remain fans speed up their RPMs?, could this be considered as a redundancy mechanism.

    Yes, a single (or a pair of) faulty fan(s) - since three faulty fans means that the entire Fan Tray is totally faulty from the cooling standpoint - will cause remaining working fan(s) to adjust their RPMs in order to keep the Aruba 3810M properly air cooled by ejecting front inlet warm air through the chassis right side (remembering that an Aruba 3810M can operate also with a faulty Fan Tray for up to two minutes)...so yes, within the Fan Tray, its fans obey to a very simple redundancy mechanism (but - still - there aren't two concurrently active Fan Trays <-- so having a spare JL088A makes sense).