Wikipedia:Reference desk/Archives/Computing/2009 October 31

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October 31

Incremental backup and deleted files

How does an incremental backup handle deleted files? --Halcatalyst (talk) 00:03, 31 October 2009 (UTC)

I assume you're talking about a situation where files X, Y, and Z exist, then you back up your hard disk, then you delete the files, and then a new increment is made. The new increment just records the fact that files X, Y, and Z have been deleted. It doesn't go back into previous incremental backup files to erase the data or anything. If and when you recover your hard disk with the backup, then those files are simply never restored onto the hard disk. (Or, I suppose, some backup programs might write them out to the hard disk and then delete them, but that would seem silly.) Tempshill (talk) 02:51, 31 October 2009 (UTC)

That's not the way I understand that incremental backups work. I think that if you create the file A and do a backup, then file A will be written to the backup store. If you then delete it, nothing new will be written to the store. So if you do a full restore, it will restore the deleted file A. --Phil Holmes (talk) 11:09, 31 October 2009 (UTC)

With incremental backup, a "full restore" requires a date. If the date is after the file was deleted, it will not be included in the full restore. -- kainaw™ 13:35, 31 October 2009 (UTC)

At best, that depends. Not all incremental backup utilities will track deleted files. Indeed, it could be argued that they shouldn't, since you may want to recover a file a while after it has been deleted. See [1] for example. --Phil Holmes (talk) 15:00, 31 October 2009 (UTC)

For example, subversion (software) requires you to commit a delete. Then, the file is marked as deleted in all subsequent revisions. In older revisions, the file is still backed up. Nimur (talk) 01:03, 7 November 2009 (UTC)

Find out IP addresses

Hi, in the Wikipedia article about Cyberstalking there is a point about tracing an IP address in an attempt to verify their home or place of employment. How would someone be able to find out someonelse's IP address? Is it possible, if so how, through the use of Facebook, MySpace, Twitter, Photobucket, etc.? And also, more importantly to some extent, how would someone block their IP address being visible on such sites and the internet in general? Thanks very much for reading this and any help and information would be much appreciated. 86.138.158.223 (talk) 00:09, 31 October 2009 (UTC)

Well, the easiest way to find someone's IP address is to have them visit a site that you have access to the server logs for. That can be as easy as sending them an e-mail with an in-line image linked to from your site -- when they open the e-mail and view the image, pow!, it connects to your server, gives you the IP address.

The only real way to block your IP is to route it through an anonymity network, like Tor. In such a situation, only the in-coming Tor node would see your IP address, and your traffic to the Tor node is encrypted.

The problem with blocking your IP address in this way is that it is very slow, on the whole (you are routing all your internet traffic through another computer, often on the other side of the globe). It also doesn't give total anonymity (see the "weaknesses" section of the article—but for many practical purposes, it would work).

Another approach would be to have as your ISP a service that was large and used dynamic IP addresses. AOL, for example, does things this way, I believe. Visits from AOL users all look basically the same—they don't give you much (if any?) information about where the user is visiting from, and they change the individual IP addresses often enough that tracking behavior by one of them is pretty hard. (Or, at least, that's the way it used to be—I don't know if it has changed in recent years.) --Mr.98 (talk) 00:53, 31 October 2009 (UTC)

Thanks very much for that. I shall use that to research further... :) 86.138.158.223 (talk) 16:51, 1 November 2009 (UTC)

BTW in case you haven't noticed, editing wikipedia without being logged in to an account also gives away your IP address. (Our privacy policy means the IP address can almost never be revealed publicly and is only viewable by a small number of people for any edit made while logged in to an account.) Nil Einne (talk) 16:58, 2 November 2009 (UTC)

Thermal paste of processor on new motherbaord

I have been using my system for three months. Now I am planning to replace my system to newly purchased motherboard. So If I attach my processor on new motherboard should I add thermal paste again on it? Bit confused. Thanks--119.30.36.53 (talk) 09:10, 31 October 2009 (UTC)

The best way of doing this is to clean the heatsink and processor of all the old thermal paste and add a small amount of new paste before attaching the heat sink. --Phil Holmes (talk) 11:06, 31 October 2009 (UTC)

Emphasis on small. See thermal grease. ---— Gadget850 (Ed) ^talk 11:11, 31 October 2009 (UTC)

Laptop Powering Down (Ubuntu 9.10)

I have a Two-year old Acer Aspire 5315 on which I have replaced Vista with Ubuntu 9.10. I'm using it more as a storage facility than anything else (even though I'm loving the new OS!) as my other Vista is down to 30GB. Anyway, as such, I need to leave it on most of the time so I can read and write data to/from it. However, I have noticed that after about 5 minutes of idling, the screen tends to dim-down over the course of around 30 seconds or so, until I am left with a blank screen. Pressing a button restores the screen, leading me to believe that this is some sort of power-saving feature. It is annoying, though, because I prefer to see the screen when I am writing to the disk from the other PC so I 'know' that files are arriving. Therefore, I want to turn off this feature (if it is a feature and not just that my laptop is buggered) but nothing changes when I open Power Management in System>Preferences and set suspend to 'never'. Is there anything else I should do? --KageTora - SPQW - (影虎) (talk) 10:01, 31 October 2009 (UTC)

Have a look at System -> Preferences -> Screensaver. --194.197.235.240 (talk) 10:20, 31 October 2009 (UTC)

Cheers! I did that just before I came back here to say 'no worries - found the solution!'. But, thanks anyway! --KageTora - SPQW - (影虎) (talk) 11:27, 31 October 2009 (UTC)

Control of Sound Card

I have a full-screen program (with accompanying sounds) that locks out Spotify when loaded ("cannot access your sound card"). Is there anyway I can forcibly remove control of the aforementioned sound card from the program - I am prepared to lose any sound from the program itself? - Jarry1250 ^{[Humorous? Discuss.]} 10:37, 31 October 2009 (UTC)

Windows Vista Service pAck

Will installing service pack 1 on vista delete my files and programs or will they be safe and unaffected?

There is no reason why installing anything should delete anything without you being asked beforehand, but, in any case, service packs are supposed to be installed. Nothing should be affected. --KageTora - SPQW - (影虎) (talk) 11:30, 31 October 2009 (UTC)

No, it will definitely not. I fact, every Windows user should install service packs as soon as they are released, for they contain important security and stability updates. --Andreas Rejbrand (talk) 12:59, 31 October 2009 (UTC)

Thanks for the answers! I'm installing service pack 1 and 2 so hopefully I'll have no more problems with windows freezing and stuff.

It is a little late, but you should always backup important files before applying MS Service Packs (or any similar "big overhaul" OS updates, whatever the OS). They can result in trouble, like the OS getting corrupted, things of that nature. They will not likely delete anything purposefully but can "break" an OS and require its reinstallation (which can "break" programs, at times). --Mr.98 (talk) 16:11, 31 October 2009 (UTC)

immedately give me answer this question.

what is the diffrence between window 98 and window xp? —Preceding unsigned comment added by Navjotkaurparihar (talk • contribs) 13:41, 31 October 2009 (UTC)

Depends what you want to know, but XP (2001) is newer than 98 (1998). XP is widely regarded as superior, if only because it offers a service which many more people will find familiar, and is compatible with a much larger percentage of (new) software. 98 is no longer supported by Microsoft and maybe therefore less secure. - Jarry1250 ^{[Humorous? Discuss.]} 13:53, 31 October 2009 (UTC)

From a technical point of view, the big difference is that Win98 is in the MS-DOS lineage of operating systems (i.e., a highly-polished turd), while WinXP is based on Windows NT, which is significantly less bad. --Sean 14:09, 31 October 2009 (UTC)

XP is very stable (if one application crashes, the entire OS will not) and secure. In XP it is possible to create different user accounts, so that person A cannot access the files of person B. Such security is not available at all in Windows 9x (Windows 95, Windows 98, and Windows ME), where person B can access the files of person A simply by opening the "C:\WINDOWS\Profiles\Person A\" folder. Furthermore, Windows 9x is antique is many other ways as well, whereas XP is a fairly usable system still, despite of its age (nine years). The most visible difference between Windows 9x and XP is the GUI - Windows XP is themed (the default theme is called Luna) by default. --Andreas Rejbrand (talk) 15:33, 31 October 2009 (UTC)

As an aside, saying "Answer this immediately!!!" is impolite, especially on a completely volunteer-based community such as Wikipedia. JIP | Talk 01:57, 1 November 2009 (UTC)

Vista Service Pack 1 trouble

I just spent an hour installing service pack 1 on vista. it reached completion, then said "Service pack did not install. Reverting changes". What went wrong??

If you Google the error message, you can find a number of pages that attempt to help. [2] [3] It sounds like it could be a whole variety of different, difficult-to-diagnose things, unfortunately. --Mr.98 (talk) 16:09, 31 October 2009 (UTC)

There will be a log somewhere on your computer with more detailed information. Check the Event Viewer and c:\windows\windowsupdate.log (which is a text file). To start the Event Viewer press Win+R to open the Run dialog and type "eventvwr.msc". -- BenRG (talk) 16:29, 31 October 2009 (UTC)

And this is one of the many reasons nobody uses Vista. HalfShadow (talk) 00:32, 1 November 2009 (UTC)

Except for the several million who do. OP, I would just try again. Tempshill (talk) 04:42, 1 November 2009 (UTC)

As one of the several million (I tried to buy XP with my laptop in 2007, but was told it was Vista or nothing, so I just configured it to look as much like XP as possible), I've had only occasional problems with upgrades, and only occasional crashes when I've had many applications open. Are you sure you had full admin rights when you started the upgrade? (Is Windows 7 stable yet?) Dbfirs 08:18, 1 November 2009 (UTC)

Windows 7 is very stable. --Andreas Rejbrand (talk) 12:46, 1 November 2009 (UTC)

Thanks. Does it allow me to configure my own desktop layout yet? (as I've been doing for twenty years). Dbfirs 09:35, 2 November 2009 (UTC)

Good anti-aliasing in Photoshop

I often find in Photoshop that I have shapes that I wish were better anti-aliased—e.g., a mask that has a very hard pixel edge. Blurring said hard edges doesn't really make them look better—they look like a blurred hard edge, not an anti-aliased one. Is there a better technique here that I am missing for taking something that has a very hard pixel edge and getting that nice, anti-aliased look? The best I have come up with is producing the mask at, say, triple the resolution, and then down-sampling (which anti-aliases pretty well), but this is not always an option. Surely there is a better way? --Mr.98 (talk) 16:58, 31 October 2009 (UTC)

What was used to create the masks in the first place? I know GIMP, not PS, but in that case if you use a soft-edged tool to make the mask, it will stay that way. --Sean 21:12, 31 October 2009 (UTC)

Presumably he's creating the masks in photoshop.

I meant "what tool?". --Sean 14:05, 1 November 2009 (UTC)

When you say you're blurring the edges, are you using the "feather" tool? By, perhaps, less than a pixel? APL (talk) 21:43, 31 October 2009 (UTC)

Work in higher resolution - double or triple the size of the image before you start. When you're done, save the high res version for the future - but drop the resolution back down again for the version you actually want to use. I'm not a big photoshop user (I prefer GIMP) - but when you drop the resolution back down - make sure you're using whatever Photoshops' best quality option is for doing that. SteveBaker (talk) 23:51, 31 October 2009 (UTC)

How are you creating the masks? The Marquee tool doesn't have antialiasing, so you should use the Path (the "pen" tool, haven't used Photoshop in a while) tool to create your mask using bézier curves instead. That gives you much nicer results and you can edit your path later. --antilived^{T | C | G} 00:10, 1 November 2009 (UTC)

So what I've found works very well in the meantime for single-color masks (e.g. black/white), is to put a 2 pixel Gaussian blur and then go to Image > Adjustments > Levels and push the white/black balance towards the center. It gives me a very nice anti-aliased edge for such images. Just passing that on. It appears that there is no sure-fire way to get the results I want (other than, as stated, working at a higher resolution and down-sampling). As for tool, I was using masks created with the magic wand tool (which claims to have anti-aliasing, but it is not very good). --Mr.98 (talk) 20:58, 1 November 2009 (UTC)

There's your problem. Use Path and you'll get a much nicer result. --antilived^{T | C | G} 22:28, 1 November 2009 (UTC)

There's an option to turn on anti-aliasing. Look on the top toolbar where you have the options for your tools; there's a check box that toggles anti-aliasing. <- this may/may not apply to masking, but the way I do making in photoshop is to add a vector mask. If you provide me with a screen shot of what you want to do, I will help you more. -- penubag  (talk) 06:12, 2 November 2009 (UTC)

Blender 3D Rendering

What factors determine how fast a scene is rendered in Blender 3D? --81.227.65.168 (talk) 17:08, 31 October 2009 (UTC)

http://wiki.blender.org/index.php/Doc:Manual/Render/Performances -194.197.235.240 (talk) 17:28, 31 October 2009 (UTC)

Sound quality

Could playing sounds from two different sources simultaneously (say, running two YouTube music videos at the same time, or a video and an online game with music) permanently degrade the sound quality on my computer? 90.193.232.242 (talk) 19:15, 31 October 2009 (UTC)

No. --Andreas Rejbrand (talk) 19:30, 31 October 2009 (UTC)

I also say no. A computer's speakers (stereologic) are made to handle different audio tracks. I'm not 100% sure, but I believe that the only way to cause permanent damage to speakers are to over modulate them by turning the volume up beyond the threshold of the voice coil and/or diaphragm (acoustics). Also, see loudspeaker for more info. Letter ⁷ _{it's the best letter :)} 00:30, 1 November 2009 (UTC)

(OP here) The speakers are fine, I can plug any speakers or headphones in and the sound will always be the same. Playing music while having a game on in the background is the only thing I do that other people don't, so far as I can tell. Vimescarrot (talk) 00:48, 1 November 2009 (UTC)