What Are You Doing Right Now
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Digging through Server log and such to see why a server cycled four times over night. As near as I can tell, the server didn't cycle,.. maybe the ISP did... I went back to my CLI Up Time
C:\Users\ntgadmin>systeminfo | find "System Boot Time" System Boot Time: 12/10/2015, 12:25:14 PM -
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
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@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
Yup,.. I looked at that first. It still reports 10/5/2015 as the last reboot
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@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
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@Dashrender said:
@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
The hypervisor puts the VM on suspend, as in stops executing all commands to and from that VM. To the VM it doesn't even realize it didn't exist for a few moment while the hypervisor rebooted.
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@Dashrender said:
@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
How can it not? The VM doesn't have any way to know that the world has stopped for a few minutes unless it has crashed or been told to shut down. To it, time just leaps forward and it doesn't remember what happened during those minutes.
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@scottalanmiller said:
@Dashrender said:
@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
How can it not? The VM doesn't have any way to know that the world has stopped for a few minutes unless it has crashed or been told to shut down. To it, time just leaps forward and it doesn't remember what happened during those minutes.
What about what was in RAM? Is that some how saved? I suppose I could understand if the hypervisor paused the VM (saving the RAM state), rebooted, then started the VM again - is that a thing? if so - huh, didn't know.
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@Dashrender said:
@scottalanmiller said:
@Dashrender said:
@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
How can it not? The VM doesn't have any way to know that the world has stopped for a few minutes unless it has crashed or been told to shut down. To it, time just leaps forward and it doesn't remember what happened during those minutes.
What about what was in RAM? Is that some how saved? I suppose I could understand if the hypervisor paused the VM (saving the RAM state), rebooted, then started the VM again - is that a thing? if so - huh, didn't know.
Yup, RAM flushes to disk. It is called a "saved state." Same as your desktop going to sleep except that the VM has no idea it is happening because the VM itself has nothing to do with it.
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@Dashrender said:
I suppose I could understand if the hypervisor paused the VM (saving the RAM state), rebooted, then started the VM again - is that a thing? if so - huh, didn't know.
It's not just a thing, it's the default behaviour
If you use VirtualBox on your desktop you will get the same thing.Think of the VM as being put into stasis. Time passes outside the VM but the VM is "frozen". When it wakes up it feels like it just blinked, but the world outside is at a different point in time.
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@scottalanmiller said:
@Dashrender said:
@scottalanmiller said:
@Dashrender said:
@scottalanmiller said:
That system OS did not cycle, but the hypervisor it is on might have, of course. What is leading people ot think that the "server cycled"?
How can the hypervisor cycle and not the VM, unless the VM is on HA?
How can it not? The VM doesn't have any way to know that the world has stopped for a few minutes unless it has crashed or been told to shut down. To it, time just leaps forward and it doesn't remember what happened during those minutes.
What about what was in RAM? Is that some how saved? I suppose I could understand if the hypervisor paused the VM (saving the RAM state), rebooted, then started the VM again - is that a thing? if so - huh, didn't know.
Yup, RAM flushes to disk. It is called a "saved state." Same as your desktop going to sleep except that the VM has no idea it is happening because the VM itself has nothing to do with it.
Is this a typical thing that one would do when needing to reboot the VM host in a non HA environment?
For example - my power outage the other day, would I have been OK just saved stating my VMs and having the host be offline for a few hours instead of shutting them down?
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That's the funny thing about memory that people rarely sit around and ponder. If I could record everything in your memory right now out to a disk somewhere... then I could dispose of your body. In five hundred years or in five million years I could take another body, load your memory into it and you would believe that "nothing happened" except whenever you looked at a watch, calendar or in a mirror you'd be confused because you can't figure out how you got where you were, why the time changed or why you look differently than you did - because you were "just" doing something else.
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LOL - sure I understand that completely. I just hadn't considered it as part of the use case with VMs. Of course there's no reason it shouldn't work for VM's like it does for end users.
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@scottalanmiller said:
That's the funny thing about memory that people rarely sit around and ponder. If I could record everything in your memory right now out to a disk somewhere... then I could dispose of your body. In five hundred years or in five million years I could take another body, load your memory into it and you would believe that "nothing happened" except whenever you looked at a watch, calendar or in a mirror you'd be confused because you can't figure out how you got where you were, why the time changed or why you look differently than you did - because you were "just" doing something else.
If you are on a buying spree and enjoy survival horror check out SOMA. It is by the same devs that made Amnesia. It uses this idea effectively throughout the entire game.
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That was a crazy amount of activity for a good 15-20 minutes there. Amazing for so early in the morning.
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Other then not having hot-swap bays... this is tempting - http://www.ebay.com/itm/HP-Proliant-DL165-G7-server-2x-12-core-AMD-Opteron-6172-48GB-RAM-750GB-HD-/221952681299?hash=item33ad692553:g:dwYAAOSwAYtWK-61
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@coliver said:
Other then not having hot-swap bays... this is tempting - http://www.ebay.com/itm/HP-Proliant-DL165-G7-server-2x-12-core-AMD-Opteron-6172-48GB-RAM-750GB-HD-/221952681299?hash=item33ad692553:g:dwYAAOSwAYtWK-61
nice - could make a nice place to play with a bunch of linux VMs
I wonder how loud it is?
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@coliver said:
That was a crazy amount of activity for a good 15-20 minutes there. Amazing for so early in the morning.
I am not complaining at all. And I think most everyone is having a hard time getting motivated to actually work
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@Dashrender said:
@coliver said:
Other then not having hot-swap bays... this is tempting - http://www.ebay.com/itm/HP-Proliant-DL165-G7-server-2x-12-core-AMD-Opteron-6172-48GB-RAM-750GB-HD-/221952681299?hash=item33ad692553:g:dwYAAOSwAYtWK-61
nice - could make a nice place to play with a bunch of linux VMs
I wonder how loud it is?
Very loud. I don't know if that has a RAID controller either. Those Opterons aren't the most power friendly.
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@coliver said:
@Dashrender said:
@coliver said:
Other then not having hot-swap bays... this is tempting - http://www.ebay.com/itm/HP-Proliant-DL165-G7-server-2x-12-core-AMD-Opteron-6172-48GB-RAM-750GB-HD-/221952681299?hash=item33ad692553:g:dwYAAOSwAYtWK-61
nice - could make a nice place to play with a bunch of linux VMs
I wonder how loud it is?
Very loud. I don't know if that has a RAID controller either. Those Opterons aren't the most power friendly.
definitely knew they are power hungery little beasts! no RAID? hmm.. might not be worth it then... have to drop a $400-$800 RAID controller ... hmmm.
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@Dashrender said:
@coliver said:
@Dashrender said:
@coliver said:
Other then not having hot-swap bays... this is tempting - http://www.ebay.com/itm/HP-Proliant-DL165-G7-server-2x-12-core-AMD-Opteron-6172-48GB-RAM-750GB-HD-/221952681299?hash=item33ad692553:g:dwYAAOSwAYtWK-61
nice - could make a nice place to play with a bunch of linux VMs
I wonder how loud it is?
Very loud. I don't know if that has a RAID controller either. Those Opterons aren't the most power friendly.
definitely knew they are power hungery little beasts! no RAID? hmm.. might not be worth it then... have to drop a $400-$800 RAID controller ... hmmm.
Software RAID... the non-hotswap is an issue too but not that bad.
