Daniel O'Connor wrote: > > --nextPart2732627.jUZ38zfOrR > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > Content-Disposition: inline > > On Sunday 13 August 2006 16:49, Peter Selinger wrote: > > Not all UPS hardward and not all drivers support ondelay/offdelay. In > > any case, you should let your system shutdown script kill the UPS, at > > the very end, after all the disks have been mounted read-only, and > > just before the system is normally halted. This will turn off your > > computer safely. -- Peter > > Any UPS worth it's salt has ondelay/offdelay (of some form) for 2 reasons, 1) > without it you can get into a situation where the UPS will not power cycle > the load if the mains comes back on at the wrong time, and 2) not all > operating systems re-mount disks read only at shutdown (eg FreeBSD runs > shutdown procedures then the kernel flushes and un-mounts the disks)
I don't see the first reason. Any UPS, when it receives the "shutdown" command, should turn off the power for a minimum amount of time before awaiting AC (just in case the AC power came on before the command was received). This minimum amount of time (typically a few seconds) is independent of any settable offdelay/ondelay timer, in fact I don't see why it needs to be settable. The second reason justifies a settable offdelay, but not a settable ondelay. Several of the newhidups subdrivers don't currently implement ondelay/offdelay. (It is, however, possible to set shutdown timers with upscmd). Almost none of the serial drivers support it (at least "grep offdelay drivers/*c" does not turn up many). > As for ondelay/offdelay having the same value - NUT disallows it and makes > sure that ondelay is longer. > > =- > Daniel O'Connor software and network engineer > for Genesis Software - http://www.gsoft.com.au > "The nice thing about standards is that there > are so many of them to choose from." > -- Andrew Tanenbaum > GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C _______________________________________________ Nut-upsuser mailing list [email protected] http://lists.alioth.debian.org/mailman/listinfo/nut-upsuser
