Wikipedia:Reference desk/Archives/Computing/2009 July 15

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

July 15

Linux server. How To.

Ok, I am thinking on renting a server from host provider the planet. They are going to give me 2 500 gig drives. At first I never saw the need for a secondary drive because I really am not sure how to navigate with a linux OS on a server. I have used Cpanel and know it well which I will be getting. So, I realized I can use the secondary drive as a backup of my database and www directory. Or entire root directory for that matter. Ok, now my question...Is there anything in cpanel I can click, or a command I can use to make sure that my mysql database and my directory is backed up to the other drive? It will be a dedicated box with root access.

I know I am better off asking someone on a tech forum. But im at work and all that is blocked. its more of a general question because it will be a bit before I get the server anyway. Ivtv (talk) 00:03, 15 July 2009 (UTC)

I strongly suspect you are getting 2 identical drives to set up RAID 1. Both drives will contain identical information. If one fails, the other still has valid data. That is a very common form of backup as it is handled by the drive controller and no software configuration in the operating system is required. As for navigating in Linux, forget the concept of drives. That is so Windows. In Linux, you have a root mountpoint. That is where you start from and it doesn't matter what drive it is on. All directories/folders are mounted somewhere under root. So, you don't jump from drive to drive. You just change from one directory to another and, if that directory is mounted on a different drive, it just happens automatically. It is also common to mount directories from one computer on another computer. For example, I have my computer's drive and I mount my personal fileserver, my work fileserver, my webserver, and my backup server as folders in my home directory. I can move, copy, edit files on any of those computers as though they are local since they are mounted right in my home directory. -- kainaw™ 00:37, 15 July 2009 (UTC)

well that is good news. yeah, I dabbled with Knoppix and Ubuntu back a few times so I have an idea on how linux works but forgot about the mounting jazz. Ill have to ask for a raid 1 configuration then if it is not default which now i am assuming it is. I would like some type of offline backup somewhere tho. For example, if users on my site decide to destroy a table or something I would not want the destroyed data to be mirrored on drive 2. I would want to go to drive 2 to get the data. you have given me some answers and I am thankful for that. Going to be awhile till i get the hardware. Thanks! Ivtv (talk) 01:18, 15 July 2009 (UTC)

I use rdiff-backup for offsite backup. It saves the changes so you can get back an old version of a file (even a deleted file). -- kainaw™ 01:19, 15 July 2009 (UTC)

SSH for mobile phones

My son tossed my phone in the pool so I now have a smart phone. I like having email on the go, but 99% of my non-spam email is a request to fix a problem on a server. I need SSH for that. I've been searching (I even called Verizon support), but I cannot find an SSH app for cell phones. Does one exist? If I can find one, I can probably get from there to one that I can force to install and run on my phone. -- kainaw™ 00:39, 15 July 2009 (UTC)

This is a long shot, but since you took the time to help me I thought I would return the favor. I personally had a look here: http://download.cnet.com/TouchTerm-SSH/3000-2352_4-10914575.html and my co worker stated look for a program called Token2Shell. Maybe you already looked, but I thought I would give it a go for you. Ivtv (talk) 02:13, 15 July 2009 (UTC)

What phone/platform is it? If it's Windows Mobile you can use PocketPuTTY which I find works quite well, the only real problem is the limited screen space, but that's more the phones fault than the application. ZX81 ^talk 02:55, 15 July 2009 (UTC)

I've never tried it, but MidpSSH is a Java/J2ME ssh client for mobile devices. Indeterminate (talk) 04:41, 15 July 2009 (UTC)

You never mentioned what kind of smart phone this is. Since you're on Verizon I guess you're not using an iPhone, but the iphone does have a few ssh clients out there, and one of them is free. Shadowjams (talk) 05:17, 15 July 2009 (UTC)

Shell in a Box exports a command line to a standard web browser using AJAX. It works pretty well. --Sean 13:57, 15 July 2009 (UTC)

Thanks all. I'm going to use the free iPhone one's source to make one for my phone. It shouldn't be nearly as hard as messing with Thunderbird to get it working on the dumb thing. -- kainaw™ 13:59, 15 July 2009 (UTC)

Best Way to Protect File

What would be the best way to protect a .doc or .odt file from other people viewing it even if they get a hold of it? I know that Word and Open Office both have password services, but how secure are these methods? Nkot (talk) 03:53, 15 July 2009 (UTC)

Their methods are usually as secure as your password. You can also use programs like winrar or winzip to compress the file and add a password to it as well. I have never dabbled with open office or word password crackers but you can get around winrar ones if your password is something simple like a dictionary word. But a password like "hE$8*9_+=!!~389jHU**&@#$" needs more computing power to crack then something like the password "JamaCa1". You can also get thumb drives that have passwords on them as well. So, technically you could go with a password for the file, password for the .rar or .zip and a password for the drive it is being stored on. Just do not forget these passwords and make them secure and at least 10 alpha/character/numeric strings Ivtv (talk) 04:40, 15 July 2009 (UTC)

Both Open Office and Word have a standardized encryption format, that if I remember right uses RC4. As the previous commenter says, they are only as good as your password, which should not be a dictionary word, and should be more than 8 characters, a combination of upper and lower case, and perhaps numbers and punctuation.

I don't think there are any public vulnerabilities in the most recent versions of these standards, but I haven't looked, and can't be sure. If you are really looking for single file encryption, there are a lot of programs out there for you. PGP and its implementations are obvious answers, but also check out List of encrypting file systems for other ideas. With these sorts of things you should always keep in mind that there is the issue of the encryption algorithm itself, (RC4, for instance, is still a very good method. it's held up well and although there are some small, academic issues with pieces of it, none of those translate to a vulnerability right now), and the system that implements it. It's this second part that gets most people in trouble. Could be a bad implementation, virus on the computer, weak password, etc. Shadowjams (talk) 05:15, 15 July 2009 (UTC)

The latest version of Word uses AES-128, and I'm not aware of any attacks. decltype (talk) 16:25, 15 July 2009 (UTC)

The password-protected Microsoft Office format does pretty strong encryption already. But, your best and most secure option is to wrap the .doc file in an encrypted archive with an unintelligible filename. By denying the viewer any information about the file-type and contents, they will have no starting point for decryption, and will essentially be reduced to brute-force guessing at decryption algorithms and passwords. (Knowing that the file is a MS Word .doc gives them a hint about what decryption method you used - and then they must only guess your password). Note that password-protection is not identical to encryption - you definitely want an encrypted archive file, so that the contents are unreadable. The ultimate question is, to what extent must you protect this data; and how much inconvenience are you willing to put up with when you want to legitimately open or edit the file? You can take data-security to an extreme; perform high-grade software encryption, and then store the encrypted data-bits on some obscure physical media (e.g. modulating the paint on toothpicks in a box that is locked in a safe inside of a secure facility). Attempting to decode this would be a pain; the information-per-volume is atrocious; but it would probably be impossible to brute-force attack, and would almost certainly be tamper-evident if anybody even tried to decrypt it at all. Nimur (talk) 22:35, 15 July 2009 (UTC)

Custom animation in powerpoint

Is there a way to REMOVE all the custom animations(from all the slides) at once in MS powerpoint 2003?Shraktu (talk) 05:12, 15 July 2009 (UTC)

Yes, but its not obvious ! In the Slide Show menu select Animation Schemes ... which displays a list of pre-canned animation schemes. Select a scheme from the Animation Schemes list - "Appear", for example - and click on Apply to All Slides. This overwrites any custom animation in all slides with the selected animation scheme. Then select "No Animation" in the Animation Schemes list and again click on Apply to All Slides. This removes all animation from all slides. Gandalf61 (talk) 11:14, 15 July 2009 (UTC)

Internet connection farts out

I've noticed this at home with both DSL and Cable modem, and a couple times at work (Fiber Optic). But sometimes it's like the entire net is dead. The throughput meters on my computer show 0Kb/s. Even when I have several webpages trying to load. And then all of a sudden (usually 30 seconds or more of no traffic), everything downloads at full speed. The fact that it has happened on different types of connections at different locations makes me think it's something more than just my computer. --68.102.170.184 (talk) 13:48, 15 July 2009 (UTC)

This is not normal behavior. I suspect that the cause of your seeing this on multiple machines might be a piece of software that you run on all your machines. It might not be network related, either; it might be that the software sometimes maxes out your CPU, which becomes 100% tasked for 30 seconds or so; does the Task Manager indicate anything like this? What happens if you quit Outlook and all the programs running in the system tray, and just run a browser? Tempshill (talk) 16:03, 15 July 2009 (UTC)

Tried not running the throughput meter? 98.14.223.143 (talk) 20:17, 15 July 2009 (UTC)

Try safemode /w networking Ivtv (talk) 21:23, 15 July 2009 (UTC)

Sorry, my Core 2 Duo stays pretty idle (around 8%) during the "blackout" phase. I'm on a Mac, but when I run Activity Monitor, there aren't any processes gobbling up RAM or CPU cycles. There's no VM thrashing. The computer is perfectly responsive -- except the network activity just farts out. (again, multiple machines, multiple browsers, multiple locations, both WPA2 WiFi and hardwired (DSL, Cable, Fiber Optic.) It's like the internet doesn't exist for 15-60 seconds and then it's back. --68.102.170.184 (talk) 12:15, 16 July 2009 (UTC)

So this happens with any type of internet connection you use, but just on this particular laptop? I can assure you that there is no such thing as "the internet doesn't exist", so in this case I can say without hesitation that there is something wrong with *your* computer. Are you sure that you are experiencing the same thing with both ethernet and wi-fi? Macs (in my experience) hare extremely fickle about wi-fi unless you happen to be connecting to an AirPort. In addition, the evidence of the problem you are looking for is probably in /var/log... --Jmeden2000 (talk) 17:02, 16 July 2009 (UTC)

Assuming they aren't jet setting around the planet you could assume that this is happening in a fairly localised location - there's more to the internet than just 'your computer' - if you think about it..83.100.250.79 (talk) 17:46, 16 July 2009 (UTC)

Happens a lot to normal people - I'd guess a problem at the local exchange. Question can you disconnect the connection, then reconnect, then try accessing the internet - does this give a short burst of activity followed by snail-net? 83.100.250.79 (talk) 17:44, 16 July 2009 (UTC)

I'm sorry if I wasn't clear. This happens on all sorts of Mac computers at work and home. Laptops, towers, iMacs. Is it possible whatever backbone my area is connected to winks out or can't handle all the traffic (I work less than 5 minutes from my home, so they could be on the same trunk... or whatever you call it) --70.167.58.6 (talk) 00:15, 17 July 2009 (UTC)

It's worth asking - if possible (though it may not prove anything if negative) - does the same happen on windows/linux etc.?

It does sound like some-sort of bandwidth throttling on the surface, which may not be intentional, though other things (such as the macs itself could be the problem) (I have had vaguely similar experiences on windows - from year to year the connection sometimes seems to be crap for weeks, then fine for months...???)83.100.250.79 (talk) 01:07, 17 July 2009 (UTC)

Computer chassis of sisal?

How likely do you think it is that a small computer which makes a computer case made of water-proofed sisal woven over a frame, will be adopted by major computer companies like Dell and HP? N.B. sisal would save energy by allowing heat to escape. (Cross-posted to science board) --Patar knight - ^chat/_{contributions} 17:42, 15 July 2009 (UTC)

Like it says at the top of the page: The reference desk does not answer requests for opinions or predictions about future events so I'm afraid you won't find an answer here and I'd recommend trying a forum instead. ZX81 ^talk 18:12, 15 July 2009 (UTC)

The theory is that this would allow us to use less fans? I don't buy it. Computers with their cases left entirely open are fully capable of overheating. It's not enough to "let the heat escape". You need to actively get rid of it. A well designed case with properly installed fans acts sort of like a wind tunnel, blowing the air right past the areas most likely to overheat. APL (talk) 18:46, 15 July 2009 (UTC)

The concept is workable (although most concepts are) - I'll give you an opinion : chance of adoption my major computer manufacturers = 0.

However chance of case using sisal fibres as a reinforcing agent is greater than 0

How about a bamboo case - they exist?83.100.250.79 (talk) 20:45, 15 July 2009 (UTC)

Try stop creating the heat in the first place :) Ivtv (talk) 21:49, 15 July 2009 (UTC)

We're already trying! It's just a lot harder than you might realize... Nimur (talk) 22:41, 15 July 2009 (UTC)

If you have a question that covers more than one desk can you redirect to just one of them - like this:

see WP:RD/S#Computer_chassis_of_sisal? 83.100.250.79 (talk) 22:45, 15 July 2009 (UTC)

Or rather, link them to the science desk instead of the science page. --antilived^{T | C | G} 06:10, 17 July 2009 (UTC)

Cell phone recharging contact erosion

I don't know what the part is called, but it's the port on the cellular phone into which you plug the non-transformer end of the charging cable into. It looks gold-plated to this ignorant user, but it's also been eroded, so much so that I'm have real problems recharging the phone. The charging cable is not at fault because other phones have no trouble with it. How much will a repair like this cost? 98.14.223.143 (talk) 20:15, 15 July 2009 (UTC)

The price of a phone Ivtv (talk) 21:12, 15 July 2009 (UTC)

Unfortunately, Ivtv's brief statement is probably correct. Modern cellular phones (along with most other mass-produced electronics) have few serviceable parts; very rarely do any distributors stock replacement parts; and technicians are rarely trained in (even simple) hardware repair. Hiring a specialist to perform a custom repair-job with custom-ordered parts would probably be much more expensive than replacing the phone. Nimur (talk) 23:11, 15 July 2009 (UTC)

I would try cleaning the contacts with alcohol, as a patina can build up on them (particularly if one lives in a humid clime). It's pretty rare for the gold contacts to wear all the way down such that they are entirely unserviceable; if this really is the case, Nimur is right - a fix is generally cost ineffective. -- Finlay McWalter | Talk 02:20, 16 July 2009 (UTC)

Lots of people use erasers for cleaning corroded electrical contacts. I first heard of it being used with the contacts on sticks of RAM, where it works pretty well. Anyway, yeah, if it's corrosion you can clean it off with baking soda or a pencil eraser, but if the plating is worn off, you probably need a new one. Indeterminate (talk) 06:16, 16 July 2009 (UTC)

Existence+

Hi guys,

Look: I'm having some more trouble with existence+. I saw my friend the other day and he was hurt pretty bad. He was all bloody.

Anyway, I don't want to "destroy" anything. I want to represent what the FUCK I want to show to the user and let HIM show me whatever.

;kjfbgkdfb (talk) 21:43, 15 July 2009 (UTC)

Wikipedia Reference Desk cannot provide psychological counseling or medical advice. Perhaps you should talk to your doctor about your concerns. Edison (talk) 21:46, 15 July 2009 (UTC)

[1] - yeah can you lose the riddles seriously - because any questions you have are just going to get deleted as nonsense aren't they. —Preceding unsigned comment added by 83.100.250.79 (talk) 22:43, 15 July 2009 (UTC)

Is there a computing question buried in there? Was this question entirely incomprehensible to everybody else? I can't find anything related to "existence+" as a software package or anything. Is it maybe a question about a user-interface? Nimur (talk) 22:46, 15 July 2009 (UTC)

I think C++ programming has sent someone insane.. (I know the feeling) Try pascal instead ";kjfbgkdfb" .Good luck.83.100.250.79 (talk) 22:58, 15 July 2009 (UTC)

Pity...He could have learned java... Nimur (talk) 23:03, 15 July 2009 (UTC)