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#92799 - 09/05/2002 12:53 Checkpoint ???
eternalsun
Pooh-Bah

Registered: 09/09/1999
Posts: 1721
Loc: San Jose, CA
I noticed how you can hold shift and shutdown windows xp (or others as well) in a "suspend" mode where upon resume it boots up some kind of stored image and the computer resumes where it was.

Is there any known software out there that continuously or at a command, checkpoints a "resume" file without shutting the computer down so that in the event of a horrible crash, I can resume to the state of the computer X hours ago?

Calvin

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#92800 - 09/05/2002 13:14 Re: Checkpoint ??? [Re: eternalsun]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
Yes. Don't trust the crap built into XP or ME though. Check into Roxio GoBack. It's quite good, and allows you to "GoBack" to a specific point in time on your computer. Or, if you deleted a file and need it back, you can mount a drive in the past and drag the file out.

And now, the main reason I recommend it above the built in stuff in XP. You blow up windows, and can't boot. Then hold a key on boot, select the time to go back to, and resume work.

This works by saving info about where data was last on the drive, and will copy it if something tries to overwrite that space. Once the buffer fills (a % of drive space set aside), it starts dumping the oldest save points. Defragging, or similar disk admin tools will overwrite the buffer quickly.

The people who wrote it (and then were aquired by Adaptec, then Roxio) are basicially virus writers. GoBack works like a virus on the system, ensuring nothing knows it's there, and allowing it to work. It's quite good, they channenged me and my co-workers to break a beta version, and we only found one or two things that could really trash it. Those have since been addressed.

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#92801 - 09/05/2002 13:20 Re: Checkpoint ??? [Re: drakino]
eternalsun
Pooh-Bah

Registered: 09/09/1999
Posts: 1721
Loc: San Jose, CA
Actually that's not what I'm looking for. If I have 10 web browsers open to different web sites, and Microsoft Word, a spreadsheet and several other tools popped open and with different tasks going on at once. I've had times where an errant program locked everything up... and I want to go back even several minutes, pretty much rewind time and back to where I was. I'm not talking about rolling back installations or changes to the hard drive. I'm talking about a running computer. I want to literally specify a point in time and the computer goes back to the exact state of those programs running at the moment. You can't say it's not possible, shut down the computer into "suspend" mode and the power goes off. When you power the computer back up, literally seconds later the programs you had running are back. I want the same functionality minus the shutdown.

Calvin

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#92802 - 09/05/2002 14:26 Re: Checkpoint ??? [Re: eternalsun]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
It's do able but can get extremely complicated as you need to save the contents of memory and the current state of the HD. Most programs won't be too thrilled if the temporary files they've been working on suddenly disappear or change contents because you've just restored to an earlier checkpoint.

If you can work out a way of patching the hibernate file to say that it should be loaded again it will sort of do what you want. But writing out the contents of memory takes a minute or two so this might be unacceptable. Suspend to RAM is quick but you've only got one copy

Would be interesting if you can pull it off though. But I don't see any thing which do checkpointing continually working that well.

I've always wanted the ability to just hibernate my PC and then just load that image up everytime instead of actually doing a full restart but as I said before, it's complicated

- Trevor

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#92803 - 09/05/2002 15:39 Re: Checkpoint ??? [Re: eternalsun]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
As tman said, it would be complicated. You would need something like GoBack on the hard drive side, and something to grab and save memory to disk every time GoBack sets a major savepoint. And while it happens, the machine would have to freeze, or have double the memory to just copy RAM real quick to then go to disk. And if something goes wrong in matching up the disk and memory, well minor things like programs crashing could occur, or if something critical is affected, Windows would blue screen.

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#92804 - 13/05/2002 14:46 Re: Checkpoint ??? [Re: tman]
eternalsun
Pooh-Bah

Registered: 09/09/1999
Posts: 1721
Loc: San Jose, CA
There's not really a heck of a lot going around file-wise, and all i'd really want is a memory hibernate-checkpoint sort of deal. I wonder why nobody has done this even in a small way? Strange.

The nice thing about hibernate is if you added devices and made hardware changes, the operating system compensates. :-)

Calvin

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