[OpenIndiana-discuss] Standard flag for fast shutdown

[Jim Klimov]

Hello all,

   Is there any standard means to signal that the OS desires
a fast shutdown as opposed to a possibly more time-consuming
"proper" shutdown? I guess the main use-case would be with
UPS events triggering the shutdown, and we want to quiesce
the system as correctly and as quickly as possible.

   For example, a VM server might elect to "savestate" the
VMs instead of asking them for complete ACPI poweroffs;
a database might wait just for several seconds before
turning off instead of waiting for every client to close
their connections, etc.

   Is there anything standardized for such flagging over
the years (i.e. a touchable file, an SMF property, etc.)
dedicated for such information?

   And on a similar note, are there any tricks for an OI NFS
server to report to its clients that it is going to shut down?
Usecase might be similar - a rebooting/UPS-shutdowning NFS
server hosting some VM images can nicely tell its clients
(VM hosts) to savestate and wait for it to come back...

Thanks,
//Jim