This is the first thing that's really made me want to get a non-iPhone.
Latitude really introduces a lot of option for apps, and not being able to do this in the background really hamstrings the device.
Hope Apple fixes this soon...
Cool! Never knew they linked to madwifi right from their FAQ... I guess I'll be buying DLink into the future, since FreeBSD supports Atheros stuff as well.
Absolutely untrue. Madwifi has support for a ton of b/g chipsets based on Atheros stuff. You can pick up a nice DLink DWL-520 for cheap, and it'll work great. (at least, that's what I think i picked up a few months ago... its something like that, at least).
The real question is how many keyloggers are actually installed and reporting back now, as opposed to last year or 5 years ago. Just becuase there are more, doesn't mean there are more actually running. This would be an interesting statistic, if someone has it.
This was my experience, nearly exactly. I had no clue what all that #define business was for, I just ignored it, didn't include it in my stuff, and moved on.
It'd be nice if I could say that years later, I understood what it was all for, and now I use it all the time, but I can't. I still have no clue. I just write in python, but I sure wish someone had explained it to me (or that I had looked for myself). It'd be nice if at least one class of one course had discussed this and potential issues that may arise.
It's not a reliable backup solution - if there is a problem, you have to fix it, or you'll just have it again, even if the recovery time is 2 seconds.
First - virtualization CAN correct hardware issues in that you can just migrate the virtual machine off the hardware, which takes between 60ms and 3s, and preserves network connections. Machine A dies? No problem, move your webserver, preserving all network connections, to machine b.
So in that case, you've just implemented redundancy quite easily, for as many services as you like.
Secondly - someone does rm -rf/, you just recover saved state
You have an attacker - recover saved state, fix hole, come back online.
As long as the disk where the state is saved is backed up from time to time, you have a backup of the operation of an OS - not just the files it uses.
The other cool thing you can do here is run a bunch of OSes each running your service. For instance, you have an OBSD, FreeBSD, Linux, and Windows server each running your pages on apache. One goes down (open bsd security hole, like always), you just put in the super-secure windows VM automatically, and you're protected from the vulnerability.
Check out the Xen User Manual. Look at the xm commands possible. You'll see one is save/restore. That is what implements the functionality I'm talking about.
Another responder mentioned live migration being much harder - he's right. He's also right when he says this is also done, with some really, extremely, very cool results.
You can migrate a Quake server from machine a to machine b iff you assume some SAN or NAS in 60ms downtime, PRESERVING NETWORK CONNECTIONS. That means if you're remotely logged into a virtual machine, and it migrates from machine a to b, you won't get logged out of the virtual machine!
This is ridiculously cool technology. Take note everyone. It seems like 80% of comments here are incorrect, however. Read the papers on the Xen site if you want to know how paravirtualization actually works. It takes time, but if you're interested, it's worth it.
One big difference (from a user perspective) is performance. Check out the xen paper here . Xen performance is often 4x better (literally) than UML because it paravirtualizes, instead of fully virtualizes. Sorry I don't have time to get into technical detail, but that's one quick answer.
Don't let that comment fool you though. Xen is much, much more. What if you organization had 4 distinct sites they wanted to host on one server? Start up 4 virtual machines, and back up their running state from time to time. If one goes down, just restart it from your clean backup IN SECONDS. Better yet, do it automatically. At the same time, Xen enforces separation from the host OS that the virtual machines are running on, so you don't have to worry about it being compromised (well, not in any way anyone has been able to demonstrate or even postulate yet).
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This is the first thing that's really made me want to get a non-iPhone. Latitude really introduces a lot of option for apps, and not being able to do this in the background really hamstrings the device. Hope Apple fixes this soon...
Cool! Never knew they linked to madwifi right from their FAQ... I guess I'll be buying DLink into the future, since FreeBSD supports Atheros stuff as well.
Absolutely untrue. Madwifi has support for a ton of b/g chipsets based on Atheros stuff. You can pick up a nice DLink DWL-520 for cheap, and it'll work great. (at least, that's what I think i picked up a few months ago... its something like that, at least).
The real question is how many keyloggers are actually installed and reporting back now, as opposed to last year or 5 years ago. Just becuase there are more, doesn't mean there are more actually running. This would be an interesting statistic, if someone has it.
It'd be nice if I could say that years later, I understood what it was all for, and now I use it all the time, but I can't. I still have no clue. I just write in python, but I sure wish someone had explained it to me (or that I had looked for myself). It'd be nice if at least one class of one course had discussed this and potential issues that may arise.
Do you even have to ask?
It's not a reliable backup solution - if there is a problem, you have to fix it, or you'll just have it again, even if the recovery time is 2 seconds.
First - virtualization CAN correct hardware issues in that you can just migrate the virtual machine off the hardware, which takes between 60ms and 3s, and preserves network connections. Machine A dies? No problem, move your webserver, preserving all network connections, to machine b.
So in that case, you've just implemented redundancy quite easily, for as many services as you like.
Secondly - someone does rm -rf /, you just recover saved state
You have an attacker - recover saved state, fix hole, come back online.
As long as the disk where the state is saved is backed up from time to time, you have a backup of the operation of an OS - not just the files it uses.
The other cool thing you can do here is run a bunch of OSes each running your service. For instance, you have an OBSD, FreeBSD, Linux, and Windows server each running your pages on apache. One goes down (open bsd security hole, like always), you just put in the super-secure windows VM automatically, and you're protected from the vulnerability.
Just use your imagination.
Another responder mentioned live migration being much harder - he's right. He's also right when he says this is also done, with some really, extremely, very cool results. You can migrate a Quake server from machine a to machine b iff you assume some SAN or NAS in 60ms downtime, PRESERVING NETWORK CONNECTIONS. That means if you're remotely logged into a virtual machine, and it migrates from machine a to b, you won't get logged out of the virtual machine!
This is ridiculously cool technology. Take note everyone. It seems like 80% of comments here are incorrect, however. Read the papers on the Xen site if you want to know how paravirtualization actually works. It takes time, but if you're interested, it's worth it.
One big difference (from a user perspective) is performance. Check out the xen paper here . Xen performance is often 4x better (literally) than UML because it paravirtualizes, instead of fully virtualizes. Sorry I don't have time to get into technical detail, but that's one quick answer.
Don't let that comment fool you though. Xen is much, much more. What if you organization had 4 distinct sites they wanted to host on one server? Start up 4 virtual machines, and back up their running state from time to time. If one goes down, just restart it from your clean backup IN SECONDS. Better yet, do it automatically. At the same time, Xen enforces separation from the host OS that the virtual machines are running on, so you don't have to worry about it being compromised (well, not in any way anyone has been able to demonstrate or even postulate yet).
The internet really is growing at an exponential rate! All those bad conference papers were true...