SMT1500I, SUA2200XLI, Mac OS 10.7, shutting down and starting two computers

[Anonymous user]

Hi

I am asking for a verification – could someone knowledgeable please read the thoughts below and reply if there are any glaring mistakes or unnoticed opportunities? It mentions opensource tools, so not strictly an APC sales question.

It is both about hardware choice and software choice, and it is complicated by Mac OS X (which has now reached version 10.7). Apparently, PowerChute Personal for mac stopped developing at 10.5. The OS built-in support for APC UPS can do basic things like shutdowns N minutes after the power cut or N minutes before full battery drain.

In our case, there are two number-crunching 27" i7 iMacs (unattended at nights and during weekends). An iMac has max power consumption of 310W. Most of the time, it will probably within 90–180W, because the screens will be off and GPUs will not be loaded with tasks.

In case of a grid power loss, we would like the iMacs to keep running for some time (not necessarily long), then shut down or put to hibernation. When the electricity comes back, they need to be switched on again.

Judging by the specs and local (to UK) discount prices, we were looking at SMT1500I and SUA2200XLI.

In order to use one UPS for two computers, we need to either somehow signal the 2nd computer to shut down from the 1st one, or use a network management card.
Signalling is problematic with standard tools: there is no place to invoke a command line in the built-in OS power settings.

This opensource daemon seems to address the problem: http://www.apcupsd.org/, so I am hoping to use it to run an ssh command instructing the 2nd server to shutdown.

Alternatively, we would have to buy two SMT1400I UPSes and use two USB cables, or buy one with a network card.

The power/price ratio and extensibility (maybe there will be more servers later) of SUA2200XLI seem very attractive, but we would definitely want to use one, shared between multiple computers.

Speaking of network cards, we can find old ones like AP9609 and AP9617 reasonably cheaply. But then again, I have my doubts about the standard software. I installed PowerChute Network Shutdown v3.0.0 to my laptop, and it seemed to start without errors. But it has very few options; there is no way to execute a command line before shutting down, which I would like for choosing a "shutdown -u" rather than a regular shutdown. Something that I found in this forum:

-u The system is halted up until the point of removing system power, but waits
before removing power for 5 minutes so that an external UPS (uninterruptible
power supply) can forcibly remove power. This simulates a dirty shutdown to per-
mit a later automatic power on. OS X uses this mode automatically with supported
UPSs in emergency shutdowns.

This would be our guarantee of powering back the servers after the electricity failure is over. Without it, not what if iMacs do not power back on? So, do we have to switch to the opensource http://www.apcupsd.org/ again to achieve restarting?

A small problematic time window will remain even then, as it seems: if the grid power comes back after the command "shutdown -u" is sent, but before UPS cuts off the actual supply. What do people do about it? Just accept as a small insignificant risk?

We would be very grateful if anybody shared their experience and corrected any misconceptions about UPSes in the text above.

Many thanks
--
Yaroslav Dmitriev

[Anonymous user · Accepted solution]

Hi

I am asking for a verification – could someone knowledgeable please read the thoughts below and reply if there are any glaring mistakes or unnoticed opportunities? It mentions opensource tools, so not strictly an APC sales question.

It is both about hardware choice and software choice, and it is complicated by Mac OS X (which has now reached version 10.7). Apparently, PowerChute Personal for mac stopped developing at 10.5. The OS built-in support for APC UPS can do basic things like shutdowns N minutes after the power cut or N minutes before full battery drain.

In our case, there are two number-crunching 27" i7 iMacs (unattended at nights and during weekends). An iMac has max power consumption of 310W. Most of the time, it will probably within 90–180W, because the screens will be off and GPUs will not be loaded with tasks.

In case of a grid power loss, we would like the iMacs to keep running for some time (not necessarily long), then shut down or put to hibernation. When the electricity comes back, they need to be switched on again.

Judging by the specs and local (to UK) discount prices, we were looking at SMT1500I and SUA2200XLI.

In order to use one UPS for two computers, we need to either somehow signal the 2nd computer to shut down from the 1st one, or use a network management card.
Signalling is problematic with standard tools: there is no place to invoke a command line in the built-in OS power settings.

This opensource daemon seems to address the problem: http://www.apcupsd.org/, so I am hoping to use it to run an ssh command instructing the 2nd server to shutdown.

Alternatively, we would have to buy two SMT1400I UPSes and use two USB cables, or buy one with a network card.

The power/price ratio and extensibility (maybe there will be more servers later) of SUA2200XLI seem very attractive, but we would definitely want to use one, shared between multiple computers.

Speaking of network cards, we can find old ones like AP9609 and AP9617 reasonably cheaply. But then again, I have my doubts about the standard software. I installed PowerChute Network Shutdown v3.0.0 to my laptop, and it seemed to start without errors. But it has very few options; there is no way to execute a command line before shutting down, which I would like for choosing a "shutdown -u" rather than a regular shutdown. Something that I found in this forum:

-u The system is halted up until the point of removing system power, but waits
before removing power for 5 minutes so that an external UPS (uninterruptible
power supply) can forcibly remove power. This simulates a dirty shutdown to per-
mit a later automatic power on. OS X uses this mode automatically with supported
UPSs in emergency shutdowns.

This would be our guarantee of powering back the servers after the electricity failure is over. Without it, not what if iMacs do not power back on? So, do we have to switch to the opensource http://www.apcupsd.org/ again to achieve restarting?

A small problematic time window will remain even then, as it seems: if the grid power comes back after the command "shutdown -u" is sent, but before UPS cuts off the actual supply. What do people do about it? Just accept as a small insignificant risk?

We would be very grateful if anybody shared their experience and corrected any misconceptions about UPSes in the text above.

Many thanks
--
Yaroslav Dmitriev