UNIX Process Cryogenics?

shawarma asks: "Due to a recent power outage, I've had to shut down a server running a process that had been running for ages calculating something. The job it was doing would have been done in a few days, I think, but I had to shut it down before the UPS ran out of juice. This got me thinking: Why can't I freeze down the process and thaw it back up at a later time? It ought to be possible to take all the connected memory pages and save them in some way, preserve file handles and pointers, and everything. Maybe net-connections would die, but that's understandable. Has any work been done in this field? If not, shouldn't there be? I'd like to contribute in some way, but I think it's a bit over my head.." Laptops have been doing this in some form for years: most laptops, when they run out of power, or when told by the user will go into "suspend" mode which is similar to what the poster is describing, however outside of laptops, I haven't seen this done. Sleeping processes also do something similar, sending their memory pages into swap so other running processes can use the memory. What, if anything, is preventing someone from taking this a step further?

Comments

Hibernation?

[GeckoX]

Is what you're asking for not just hibernation?

Fully available on Win2k/XP etc, works just a treat.

No idea of anything comparable elsewhere, i.e.: for linux but the concept is neither new or unheard of.

Really worth the effort?

[NetJunkie]

How often is this a problem? If it happens a lot fix the power problem...not the problems after.

I don't see it worth the time and effort to set something like this up.

WinXP does this on my laptop

[jon_c]

But its called hibernation. Bassicly all the processes are suspeneded then the system memory is copied to disk. The tricky part is getting the devices to hibernate. The way MS handles it is that all the active devices have to support the hibernation calls or the entire system won't hibernate.

I'm sure other OS's have this too, i wouldn't be suprised if someone has done it with linux.

-Jon

No need, my good man

[JohnTheFisherman]

The answer is 42. :D

Volgons?

[wiredog]

The bastard children of Vogons and Vorlons?

Microsoft

[volpe]

Why can't I freeze down the process and thaw it back up at a later time? It ought to be possible to take all the connected memory pages and save them in some way, preserve file handles and pointers, and everything. Maybe net-connections would die, but that's understandable. Has any work been done in this field?


Yes, in Redmond. It's called "Hibernate Mode", and it's been around for a while now. If the truth hurts, go ahead and mod me down. My karma's capped at 50 right now anyway.

Re:Use Windows XP

[Ewan]

I did wonder, i also got an overrated and an underrated :)

the answer

[stinky wizzleteats]

was 42. The question is suspected to be 6 X 9.

Damn Vogons.

^Z

[Rogain]

But seriously....