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May
15
comment Is a Windows 7 System Image a literal copy of the sectors on the disk?
Do you know of anything that could be described as a "Windows 7 System Image" that copies the contents of free space?
May
15
comment Connecting to a network printer through a wireless AP
Exactly. Use it only as an access point. (Turn off its DHCP server, don't use its WAN/Internet port, and so on.)
May
14
answered Is a Windows 7 System Image a literal copy of the sectors on the disk?
May
13
comment How is a public ip adddress accessible anywhere from the internet?
@Ashwin: There are two possible reasons: 1) You may be looking in the wrong place in the ipconfig output. There's a separate block for each interface. 2) You may have a default route that's not an interface route, which ipconfig won't show. (The route print command will show it. It'll be the route with both a destination and netmask of 0.0.0.0.)
May
13
comment How is a public ip adddress accessible anywhere from the internet?
You can see the path the packet took, specifically where it went immediately after it left your machine. If you traced the route to a "random" external IP, then the next hop should be your default route. (Assuming your machine doesn't have a full Internet routing table, which it almost certainly doesn't.)
May
13
comment How is a public ip adddress accessible anywhere from the internet?
I agree with Rapzid. The last part of the answer is needlessly complicated and generally incorrect. A simpler explanation is this: Routers close to you have routes "up" towards routers with more information about the Internet (a typical home user, for example, gets the packet 'up' to their provider). At some point, you reach a router that knows a route towards the destination's network (core routers exchange this information with each other). The packet eventually reaches a router close to the destination that has a route "down" to the destination.
May
13
comment How is a public ip adddress accessible anywhere from the internet?
@Ashwin Your computer is not giving you useful information. You can do a traceroute to see what the next hop is. (The command is tracert on Windows.)
May
13
comment With Xen, when is Swap used?
If you have significantly more free memory than vm.min_free_kbytes, that indicates that memory is free because the system couldn't find a way to use it. That's common at system startup, since not much data has been read from disk yet. And it's common when a process with a lot of memory usage terminates, because the system hasn't found a new use for that memory yet. If you consistently see a lot more free memory than the minimum, that indicates your system has a lot of 'churn', that is memory that is being released.
May
12
comment With Xen, when is Swap used?
By the way, the command sysctl vm.min_free_kbytes will tell you how many KB the system believes it needs to keep free. You can tune this value, and for low-memory systems, it's usually safe to reduce it by 30% or so. Keeping less memory free means more memory can be used, improving performance. The risk is that the system may not have enough free memory to cope with a large burst of disk or network load. (But the default is conservatively high. So lowering it is usually safe.)
May
12
comment With Xen, when is Swap used?
What did others tell you that contradicts what I said?
May
12
answered With Xen, when is Swap used?
May
12
comment What benefits are there to enabling STP on a WiFi access point?
That device is not a bridge, it's simply a client end station. Its point is not to relay all network traffic to its wired connection, and it can't be used for that purpose. Its point is only to connect a single end station to a WiFi network as a client. In any event, even it tried to bridge, it wouldn't work because an access point will not bridge to a client. That's why you need to configure WDS in the access point as well as the bridge.
May
11
comment What benefits are there to enabling STP on a WiFi access point?
That can't happen. A WiFi bridge will not make itself a client to an access point because the bridge (unless it's fundamentally broken) knows that unicast won't work in that configuration. Broadcast loops would be the least of your problems, and WiFi bridges are smart enough not to set up configurations that can't possibly work at all.
May
11
comment What benefits are there to enabling STP on a WiFi access point?
No, you won't. Since the wireless bridge is acting as a client, the access point will not send it packets not bound to its WiFi hardware address, nor will it accept from it packets not from its WiFi hardware address. The WiFi protocol was designed this way back when it topped out at 11Mbps -- bridging by default to 100Mbps networks would have been bad.
May
11
comment What benefits are there to enabling STP on a WiFi access point?
Nothing will happen unless the configuration of the access point is changed (for example, enabling WDS). The access point will only talk to its clients, not devices they bridge.
May
10
comment how to use a disk with high reallocated sector count?
Not likely, because modern drives distribute the spares so the performance affect isn't usually noticeable. There's nothing special you need to do. If you want to keep using the drives, run a few full read/write passes over them to shake out any about-to-fail sectors and hope for the best.
May
10
comment how to use a disk with high reallocated sector count?
It's not clear why you think you need to do something special. The excerpt from the Wikipedia article is about how to preserve drive speed. Is that what you're trying to do? Is your issue with these drives performance?
May
10
comment Clarification about Linux TCP window size and delays
Application-layer acknowledgements would have solved this problem tool (by getting the ACKs back faster) and that wouldn't require any system-level tuning. (If you can always tune the systems this software runs on, then this is simpler. But if you can't, you should add application-layer acknowledgements.) Nice detective work, by the way.
May
9
comment How do I limit MS SQL Server memory usage?
@wfault: "By default, SQL Server can change its memory requirements dynamically based on available system resources." Many people like to mess with things just for the sake of messing with them, but what they're actually doing is inhibiting the server's ability to tune itself to changing load. If it ain't broke, you can't fix it. This is most commonly done by people who like to see lots of free memory to make themselves feel good, but actually, any memory that's free is also unused -- that is, wasted.
May
9
comment How do I limit MS SQL Server memory usage?
"Bargaining room"? Most likely, you should just leave things alone. The people who designed these things knew what they were doing, and unless you know something they don't, their decisions are probably best. Remember, any free memory is forever wasted. It's not like if you use half your memory today you can use twice your memory tomorrow.