Uptime recommendation?

[morecomplete_apc]

What are the advantages and disadvantages to long vs short uptime. I've always configured my units to keep the server up as long as possible before graceful shutdown however, I recently had an issue... The power went out, and then came back on just as the UPS is shutting down the server. THEN it went out again! The UPS will at that point was low on battery power and unable to perform a graceful shutdown. I figure the odds of this happening are slim but now management is asking that I look into mitigating this risk. Any help is appreciated. Thanks.

[TheNotoriousKMP_apc · Accepted solution]

I have attached a screenshot of where it is available to configure within the APC Agent's web interface. To access that:

HTTP://:3052

Use the username and password that you use for the console to log in here.

[morecomplete_apc]

This helps a lot. Thanks again!

[morecomplete_apc]

Excellent, thanks! That really helps. Just out of curiosity, what are the best practices? What does APC recommend?

Message was edited by: morecomplete

[TheNotoriousKMP_apc]

You could always configure a return delay on your UPS/Network Management Card to have a minimum return battery capacity before it turns back on to prevent this from happening again. Downside: What's the actual chance of this happening again?

The disadvantage to a ton of runtime is that recharge time can become quite substantial. The disadvantage to minimal runtime is that you would have to wait a lot longer to meet your minimum return delay requirements on your UPS.

[morecomplete_apc]

I'm not sure if I have the capability to configure a return delay to have a minimum return battery capacity before it turns back on. I am using PowerChute Business Edition Deluxe with SU3000s and do not have a network card. Just the rs232 running to the server. Can I still do this with my setup? What are my other options?

I think the chance of this happening again are slim and have always been of the opinion that the server should remain up as long as possible. However, I find myself now having to defend this position and I don't have much ammo other than "that's the way I've always done it". 😉 Somewhere along the way I heard this was best practice and that the only downside was a shorter battery life.

[TheNotoriousKMP_apc]

We can't really make any recommendations because every customer is on a different part of the grid and is succeptable to different power issues. In your issue, you know have to protect against a blackout immediately following power restoration caused by a blackout. Depending on your runtime/load %, and how you have your shutdown scheduled, you may want to test at what battery % is your runtime equal to the total amount of time it will take for everything to power down, and then select the next best available return battery capacity.

[morecomplete_apc]

"you may want to test at what battery % is your runtime equal to the total amount of time it will take for everything to power down, and then select the next best available return battery capacity."

Okay, sorry I'm a little slow here but how exactly do you test this?

[TheNotoriousKMP_apc]

This is only going to be valid if you have a shutdown sequence scheduled. If so, what you would want to do is simulate a power failure with the entire load that's going to be handled by the UPS. Watch the battery capacity and runtime decrease. When the load begins a shutdown procedure, note the battery capacity. That is what you will want your minimum battery capacity to be GREATER than. You will need at least that much runtime/capacity available upon UPS Power restoration to prevent from another immediate shutdown.