redfish: always do off/delay/on for power cycle #149
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This would only affect the cycle command, right? Seems like that one's probably not all that commonly used anyway... |
| send "cycle %s\n" | ||
| send "off %s\n" | ||
| expect "redfishpower> " | ||
| send "on %s\n" | ||
| expect "redfishpower> " |
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Usually we put a delay in here?
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lol, i guess the one i copied and pasted from is missing a delay. I'll fix up everywhere.
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i just remembered that delay isn't strictly necessary here because we "wait until off" for the off command. But a couple seconds delay couldn't hurt since that is the common pattern.
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The delay is to actually have the hardware in the off state for a period of time before reapplying power. The "wait until on|off" thang is presumed to be how things work throughout powerman.
Problem: When a power cycle is implemented as an off followed by an on, a delay between the two is typically added in case the system needs to "settle" a bit. This is not strictly necessary for redfishpower, since it verifies the power is off before performing the on. However, since it is the common pattern in powerman, it couldn't hurt to add a small delay just in case the system needs "settling" time. Add a small 2 second delay in cycle_ranged in etc/devices/redfishpower-cray-windom.dev.
Problem: A native power cycle with the redfish protocol is inherently racy. After performing a power cycle and immediately getting the power status, there is no way to know if the power status of "on" is from before or after the cycle. This can be confusing to users. In all redfishpower devices files, define power cycles as an off, delay, and on. Do not use native redfish cycle/restart. Fixes chaos#148
Problem: We now define all redfishpower cycles as an off, delay, and on. Some configuration notes are now out of date due to this change. Update redfishpower configuration notes to account for this change.
Problem: Due to the raciness of power status after a power cycle, we now define power cycle as off, delay, on in all redfishpower device files. Now power "cycle" is no longer needed in redfishpower. Remove all power cycle support in redfishpower. Remove all documentation in redfishpower(8) as well.
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re-pushed adding an extra commit to add the delay. Wanna take an extra skim @garlick? |
Per discussion in #148
I think the first and second commit are pretty obvious given the discussion.
Commit number 3 is more debatable. It would break backwards compatibility if anyone copied/modified an older redfishpower device file.
The primary reason I wanted to go down this path to remove redfishpower "cycle" is b/c parent support (#81) cannot work with native power cycle b/c of the inherent raciness of checking the power status after a power cycle.