Wikipedia:Reference desk/Archives/Computing/2014 April 1

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.

April 1

Distinguishing locations on Google Plus

I agreed to Google Plus for YouTube reasons, but prefer to stay somewhat anonymous. So I said I live in The Milky Way. Not a lie. However, my profile map points people to this very specific breast pump store in Charlotte. That's a total lie. Never been there, and I hate babies.

Can't figure out how to tell it I mean the other one. If it's impossible, that's fine. There are probably worse places to claim you're from. But Google Earth has a Sky View, so can it be done? InedibleHulk (talk) 01:18, 1 April 2014 (UTC)

Portable drive - HD vs. SSD

I'm considering using a small portable drive containing important files to go into a bank safe deposit box. It will be updated maybe twice a year and will remain there for years. Which is likely to be working in several years, being stored in a safe deposit box - HD or SSD?

(I also use other backups, including online storage, but they delete things from their computers 30 days after the user deletes them. I don't want to find out that I deleted my photos more than 30 days ago.) Bubba73 ^{You talkin' to me?} 04:26, 1 April 2014 (UTC)

Really what you want is data about the long term storage survival of SSD vs HD. I don't know that offhand; I'd probably google for it just as you had. My guess is that if you're worried about the HDD you could add some parity files (par / par2) and you could easily recover from any errors. Optical media has some desirable properties when stored long term too. There's a library of congress report on long term storage whose like I can't quickly find but it's out there, and it's a few years old, but it talks about this sort of thing. I would note that the SSD on flash drives is similar to the SSD on full drives (I'm sure someone else can correct me here). Shadowjams (talk) 05:12, 1 April 2014 (UTC)

Right now I've got CDs and DVDs in the safe deposit box. But they are inconvenient to make and update. Also, just plain thumb drives may do the trick. Bubba73 ^{You talkin' to me?} 06:00, 1 April 2014 (UTC)

I'd go with a RAID-like array of thumb drives. No need to get two copies of every file; just use one as parity storage. This will ensure that you can read all your data even if one entire flash drive is dead. ooze 06:38, 1 April 2014 (UTC)

I've never heard of a RAID of thumb drives before. But now I'm leaning toward a 128GB USB 3.0 thumb drive. Bubba73 ^{You talkin' to me?} 06:44, 1 April 2014 (UTC)

It doesn't have to be a fully functional RAID, though. For backup purposes, you only need the parity, which lets you survive one major failure. So, rather than two 128GB drives, you can use 3 64GB drives, which might be cheaper (and faster, if the individual 64G drives are as fast as the 128G drives). Parchive (mentioned below) is one popular tool for this.

It is quite important to verify after backup; some flash drive firmware is flawed, and doesn't disconnect properly. - ¡Ouch! (^{hurt me} / _{more pain}) 06:09, 2 April 2014 (UTC)

• Oh. I get a sense of fear and foreboding over this idea. Not all thumb drives are created equal. Also, you only have to have some unplanned event like a long period of sickness or a protracted house move (I once spent a year in temporary accommodation with all my stuff in storage) etc. and you could lose data. This short blog throws light on some of the issues one has to consider with this sort of solid state technology. Data lifespan on SSDs One thing it doesn't mention is that solid state memory is like millions of little radiation sensors and if you are store them in an area with high background radiation your photos may go home to that big Cloud in the sky even sooner. Finally, You don't have to sit and watch a DVD being burnt. I do my back up whist watching TV.--Aspro (talk) 08:29, 1 April 2014 (UTC)

High background radiation? I wonder if that one can happen with a bank safe. I wouldn't be happy with it anyway, for other reasons, like Who the hell put radioactive material in a bank safe? - ¡Ouch! (^{hurt me} / _{more pain}) 06:09, 2 April 2014 (UTC)

Yea, but I'm kind of a backup fanatic - in 33+ years I've lost very little data. Important stuff on my main drive gets backed up to the second drive on the same computer, to an external drive, to another drive on our home network, and to could storage. With another backup in the safe deposit box at the bank, I'm pretty well covered against anything. If my house is destroyed I've got the other two. If I lose something and don't realize it for more than 30 days, I've got the one in the bank. If the city is destroyed by a hurricane, I've got the one on the cloud. (And I've got 61GB of photos, 10GB of sound files, plus a few more GB of important stuff.) Bubba73 ^{You talkin' to me?} 17:54, 1 April 2014 (UTC)

Well in that case, if you reformat and rewrite each time you update, then a thumb drive will probably still be going long after the USB standard has become obsolete. Place it a sealable plastic bag with a small silica gel sachet and write on the bag what is inside. This helps when you are in a hurry and will help to preserve the drive from corrosion. Make sure you buy a good quality thumb dive that is not meant for enterprise use but for domestic use, as these will store data for longer.--Aspro (talk) 20:12, 1 April 2014 (UTC)

Both are dubious for long term data storage. Flash memory, especially cheap flash using 3-level cells, has limited data retentivity, while hard drives often fail mechanically if left unused for long periods (lubricants dry out, etc). Your best bet is probably either tape or optical discs. Your 80 or so GB of data would be around 15 or 20 dvd's, an inconvenient but probably still practical amount, plus you'd want some redundancy using something like parchive format. Amazon Glacier is an online storage product intended for long term archiving and is pretty affordable at the scale you're talking about. If you want to archive stuff on your own media, you really have to keep refreshing it now and then, maybe on World Backup Day (March 31) every year. 70.36.142.114 (talk) 01:21, 2 April 2014 (UTC)

Thanks, Glacier sounds interesting. I used tapes 10 or so years ago - I thought they were obsolete. Just a few days ago I made a five-DVD system recovery system, and that was painful. This is for an off-site backup, just in case it is needed. Bubba73 ^{You talkin' to me?} 05:18, 2 April 2014 (UTC)

If you go the flash drive route, I recommend that you only purchase flash drives from major retailers (brick & mortar stores or a few well-known online sites) that have trusted supply chains. Sources like eBay and Amazon are flooded with fake-capacity generic drives (and counterfeits). These drives have apparent capacities 32GB - 512GB, but are actually low capacity drives (typically 4, 8, or 16 GB) that have been hacked to make them appear high capacity. Files will write without errors, will look okay in folders, but any data written past the true capacity will be irretrievably corrupt when read back. 24.254.222.118 (talk) 01:51, 3 April 2014 (UTC)

Thanks for the information. I've already ordered a 128GB PNY thumb drive from Amazon. I will check it carefully. (I've been burned twice by fake batteries - once for a camera; once for a laptop.) Bubba73 ^{You talkin' to me?} 02:13, 3 April 2014 (UTC)

To expand on my commands above, Amazon listings stating "ships from and sold by Amazon.com" should be fine. It's the third party sales that are a mix of good and bad. Also, as far as I know, PNY is not one of the commonly counterfeited brands. 24.254.222.118 (talk) 08:47, 3 April 2014 (UTC)

This is directly from Amazon, not a third party. I will examine the packaging. I will copy my photos over to it - that will make it more than half full. They are organized by month, so I can test one month each year. Bubba73 ^{You talkin' to me?} 20:16, 3 April 2014 (UTC)

I got the 128GB PNY today. I checked the package to make sure the fine print was sharp. I copied the photos over, which filled up more than half of it. They are stored in folders by year, going back to 2001, and by month within year. I checked one from each year and they are all there, so it is OK. Bubba73 ^{You talkin' to me?} 17:58, 5 April 2014 (UTC)

Resolved

My 128GB thumb drive is on the way. But 500GB portable drives are only US$50-60, so I might get one of them too. Bubba73 ^{You talkin' to me?} 04:44, 4 April 2014 (UTC)

DD WRT bricked with TTL=64

For some reason the forum captcha hate me because I already entered the correct code but it always fail with incorrect confirmation code

I'm using DIR 300 with build 10/10/9 and it just fail, it doesn't respond to web interface and telnet and SSH, I have tried 30/30/30 reset but it doesn't work, I've ping it from the same subnet and it returns with TTL=64, and according to the peacock thread that router isn't bricked...

Can someone help me? 118.136.4.150 (talk) 11:34, 1 April 2014 (UTC)

Ideas for best way to display text with QR Codes

Hello. I'm looking to have a sort of QR code scavenger hunt in our city and am wondering what options I have for displaying text with a QR code. I'm aware that you can store actual text in a code, but that it's usually limited to only around 300 characters. I could link to a blog, Wordpress or something, but I'd rather the text appear in a more basic looking way. Is there someth other platform for me to upload text that would look nicer than a blog? Is Dropbox compatible with smartphones and could I upload a text document, or what that be a hassle to the users? I'm just brain storming right now, so any ideas would be appreciated. Thanks! 74.69.117.101 (talk) 12:41, 1 April 2014 (UTC)

You can find some very low cost web hosting platforms and then build each text as a page, in mobile-friendly HTML, yourself. A simple templating mechanism like Jinja or Handlebars can build the pages so you don't have to code each page by hand. Because the URLs are embedded in the QR codes, the "site" doesn't need any navigation, links, etc. A practical problem you'll find is that plenty of smartphones don't come with a built-in QR reader - this post says neither Android nor Apple phones do. This story suggests fewer than 20% of smartphone users scan QR codes (suggesting only about that percentage know what they are, what to do with them, and have installed an app to handle them). So you'll have to prepare your scavengers to make sure they can read the codes (presumably with some information several days beforehand). -- Finlay McWalterჷTalk 12:54, 1 April 2014 (UTC)

Thanks. I'll look into your suggestion. I don't even have a smart phone haha : p 74.69.117.101 (talk) 18:04, 1 April 2014 (UTC)

Of course, one must ask "is 300 characters insufficient"? -- SGBailey (talk) 10:38, 2 April 2014 (UTC)

We're planning on having a story go with the codes, but I'm thinking it might be best to just have spots with two or three codes. 74.69.117.101 (talk) 12:49, 2 April 2014 (UTC)