Wake on Lan, Jails and if promiscuous mode

[hsaff]

Hi there,

I am trying to familiarise with jails. While doing this I like to wake up my NAS through Wake on LAN /WoL. Now with installing jails and their interfaces in promiscuous mode, the WoL capabilities of the parent interface went away.

Is that behaviour interface specific or does it happen by design of Jails? I would like to keep the WoL capabilities (older, power consuming hardware).

Hav not found documentation about that issue.

Regards

 

[Scareh]

well WOL is hardware specific, that would explain why you don't find anything on it inhere, so you're kinda on your own on this i'm afraid.

I know my WOL worked when i was testing on older hardware (even with jails), so not sure.
Not entirely sure what you mean on the "promiscuous mode" either.

 

[cyberjock]

WoL also isn't discussed in the documentation because it's effectively "use at your own risk". It's not endorsed or recommended and there's lots of evidence that spinning up and down disks, while potentially saving power, also means you are much more likely to RMA the drives due to wear and tear. 24x7 spinning disks seem to last longer for whatever reason.

 

[hsaff]

@ Scareh: promiscuous mode means that the additional interfaces created with jails are bound to the network more likely as a hub than as a switch. In promiscuous mode the interfaces see all traffic directed to the parent, physical interface (hub mode) instead of traffic just addressed to the target jail (switch mode)...I want to use this for e.g. traffic analysis with wireshark or ntop/nprobe.

@ cyberjock: I believe you, but it depends on how much you wear out the drives compared to the time the machine is off. If in average 1/3 of the time (or 8h a day - typical home use) the machine is off with 20% shorter lifetime during operation, the overall lifetime (including the power-off time) would be 13% higher than with 24/7. In addition I measured the power consumption: in sleep state 1.4 Watt, in operation 40 Watt!

So no definite answer if you can reconfigure WoL on jails or the parent interface?

Regards

 

[cyberjock]

@ cyberjock: I believe you, but it depends on how much you wear out the drives compared to the time the machine is off. If in average 1/3 of the time (or 8h a day - typical home use) the machine is off with 20% shorter lifetime during operation, the overall lifetime (including the power-off time) would be 13% higher than with 24/7. In addition I measured the power consumption: in sleep state 1.4 Watt, in operation 40 Watt!

I totally agree. The real problem is that there is no qualitative evidence of "how much" wear is equivalent to shutting the machine off and where that threshold is that makes it better to leave it on all the time. We do know that spinning down the disks more than once a day is severely skewed in the benefit of leaving them on 24x7. Now when it skews in favor of leaving the disks off is definitely something that could be argued from either side with no solid evidence either way. It's just been an observation by quite a few storage enthusiasts that its just not worth the spinup and spindown. I personally don't shut my server down except for thunderstorms, regardless of whether I'm going on vacation for two weeks or not.

 

[hsaff]

...should be last reply to this topic:

I made some tests with jails and the outcome is: with the 'virtual network'/ VIMAGE and Vanilla the interface goes into promiscuous mode which seems to override most of the existing interface features. With a jail without VIMAGE and Vanilla the interface features stay the same. The jail will be accessible just as an alias of the existing interface.

As my FreeNAS jail should act as a gateway between two subnets, I need to configure this as a 'standard' jail with all apps just within the same jail (Wireshark, ntop). I will not see traffic directed to FreeNAS itself as a NAS/ network share, but all other traffic should be seen as the jail become the 'default gateway' for the subnets where the clients are hosted.

Some drawback, but Wake on Lan is essential to me due to the power consumption.

Regards