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Author Topic: Advice for Testing USB Sticks and Data Recovery Tools  (Read 4390 times)
brahman
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« on: July 04, 2009, 04:33:55 AM »

Hello,

in my experience with USB sticks a brand new purchase may have a problem right away. If so immediately return it and do not use it. There were also a lot of fakes on the markets, which had a real size  of only 512MB, but made Windows think successfully that the size was several GB. It also allowed Windows to copy data in that amount (built the Fat with the filenames so that the files appeared to bo on the stick even when searchng for them later, but all the data went into the toilet WITHOUT ANY ERROR MESSAGE WHILE COPYING). These fakes can only be detected with special tools, since the controller is adjusted to show let's say 8GB, but there is only 512MB memory in it. Worse, problems will only show up, if you try to put more than 512MB of data on this stick and afterwards check all the data with a compare utility, since the file is registered in the file system and any file commander shows it to be on the disk, though it is not.

Because of wear leveling (the controller switches data to different sectors to increase life expectancy of the memory chips on write operations) USB sticks cannot be easily handled by standard hard drive diagnostic utilities. One give away for a fake stick though is a GRAPHED speed bench mark test: The REAL chip will be slow, and then the rest of the test will show unrealistically FAST results.

Like this fake 1 GB USB drive with only 256MB on board where the real chip is about 12,5MB/sec but the stick controller lets the data pass for the non-existent chips at 25MB/sec.:



There is one free utility specially for USB sticks which a big German software magazine developed after they sent out a few hundred (at least) of those fake sticks to their users as gifts for subscribing to their magazine (and subsequently had to replace them all!).

I run this tool on all my USB sticks when first purchasing them.

It works best when the stick is formatted but completely empty, since it fills the stick up to capacity with its own data and then makes a byte by byte comparison. This way it bypasses the wear leveling and caching of the USB stick and can test every single sector. I would recommend to format the stick as Fat/Fat32 for testing, and only after first testing format to NTFS if so desired.

The program itself can be switched from German to English when started, but the web site is German only.

Here is the link to the website translated by google:

http://translate.google.c...istory_state0=&swap=1

Here is the original German link:

http://www.heise.de/softw...re/download/h2testw/50539

Here is the link for directly  downloading the utility (which is a bit difficult to find):

http://www.heise.de/ct/Re...downloads/h2testw_1.4.zip

If you do have data problems on a stick already in use, I would recommend the excellent free Testdisk and Photorec. Run Photorec first to lift any problem data from the flash memory before starting the Testdisk repair procedure, since sometimes any repair attempt could theoretically make things work, so it is best to always do a recovery first.

Also another highly recommended program for most data recovery problem (USB stick use for free, hard disk use you need to buy the program) is Zero Assumption Recovery, which you can buy on a weekend with their special weekend discount for $29.95, but as said: Recovering photos from flash is free.

I have all of them in my tool kit, and they are must have for me.
 
One last piece of advice: Windows Checkdisk in error correct mode should only be run as a routine maintenance tool for very minor problems related to the file system. Do not run chckdsk if there is already a hardware or more serious data integrity problem, it can make things considerably worse and potentially unrecoverable. Always lift the data off first ( ... on a USB stick, slightly different story on a dying mechanical hard drive, but that would be another topic ...).

Hope this helps some.

Regards,

Brahman
« Last Edit: July 04, 2009, 11:20:30 AM by brahman » Logged

Regards, Brahman
Innuendo
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« Reply #1 on: July 04, 2009, 09:21:46 AM »

Wow, good advice. I haven't heard anything about fake USB sticks lately, but I haven't been seeking the information out. Last I checked eBay was over-run with them. A good rule of thumb is only buy reputable brand USB drives from reputable vendors.

Sounds simple enough, but for some reason common sense flies out the window when a person goes shopping online for a USB drive. They see 8, 16 or whatever GB for something ridiculous and don't think it through. If it sounds too good to be true it usually is.

What used to be the dirty little secret of the USB drive industry was how hard it was (is?) to find the read/write speeds on every drive. Sometimes two different brand drives which are otherwise identical have radically different read and write capabilities. Sometimes for just about the same price you can get a drive that's 3 times or more faster than its competitors.

And to further extend on the point of fake drives reporting fake drive space the first thing I always do is find some h-u-g-e files and copy those files to entirely fill up the new flash drive. Then I copy them back to my HD & run a compare on the original files vs. the copy that just made the trip to the flash drive and back. Test results should report the file sets as being identical or you've got a problem.

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Curt
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« Reply #2 on: July 04, 2009, 10:19:06 AM »

Most interesting thread. All was new to me. Thanks for telling!
 thumbs up
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brahman
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« Reply #3 on: July 04, 2009, 11:06:58 AM »

the first thing I always do is find some h-u-g-e files and copy those files to entirely fill up the new flash drive. Then I copy them back to my HD & run a compare on the original files vs. the copy that just made the trip to the flash drive and back. Test results should report the file sets as being identical or you've got a problem.

Yes - that is the best test procedure for new USB sticks and that is exactly what the tool h2testw from the German Heise magazine publisher (link above) does, but all on the push of a button and in one whole swoop!  Thmbsup

Regards,

Brahman
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Regards, Brahman
Innuendo
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« Reply #4 on: July 04, 2009, 12:04:08 PM »

Then I'll be keeping that tool in mind if/when I get another flash drive. Right now I have an 8GB Sandisk Contour and the only way I can see myself replacing it is if it were lost or I outgrow it.
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4wd
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« Reply #5 on: July 04, 2009, 10:44:37 PM »

For a more detailed look at your USB Flash devices you can also check out ChipGenius, (Google translated).



Quote
ChipGenius (chip Wizard) is a USB device detection tool-chip models, it will automatically query disk, MP3/MP4, card readers, mobile hard drive and all USB devices chip control models, manufacturers, brands, and provide relevant information Download Address.  Of course, can also access the USB device VID / PID information, device name, interface speed, serial number, equipment and other versions.
Small green software, plug-and-play, digital consumer electronics enthusiast, DIY and maintenance personnel digital good helper around.

After analysing a drive it can also provide a link to a production tool suitable for that drive that can allow you to change various parameters of the drive, eg. you can turn it into a virtual writable CD drive - or render it useless if you screw up.
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MerleOne
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« Reply #6 on: July 05, 2009, 04:34:02 PM »

I had once a fake USB key, supposedly 1GB, actually only 512MB.  The HP USB Format Tool was able to reformat it to its real size. It has been working nicely since then.  Other keys, that weren't reformatted, got damaged after a while, probably whe  more than 512 MB was written.

To test them, I also rely on a similar tool, Bart Stuff Test (http://www.nu2.nu/bst/).
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brahman
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« Reply #7 on: December 28, 2009, 11:11:39 AM »

Found an even more comprehensive testing program for USB Flash Drives: Check Flash

For simplicity I use h2testw but for more comprehensive stuff I use Check Flash now.

Regards,

B.

P.S.: Same link as above is another nice proggie: Video Stress Test to check your graphic card's memory.
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Regards, Brahman
MilesAhead
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« Reply #8 on: December 28, 2009, 11:41:05 AM »

I had once a fake USB key, supposedly 1GB, actually only 512MB.  The HP USB Format Tool was able to reformat it to its real size. It has been working nicely since then.  Other keys, that weren't reformatted, got damaged after a while, probably whe  more than 512 MB was written.

To test them, I also rely on a similar tool, Bart Stuff Test (http://www.nu2.nu/bst/).

One thing I noticed with a USB key I formatted. It seems obvious but easy to forget in the rush of the moment.  I did a quick format to another file system type.  Later after showing a file successfully copied, it would not read it all back out.  A full format as NTFS fixed it.. even just using Windows shell format.

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MilesAhead
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« Reply #9 on: December 28, 2009, 11:48:33 AM »

...

What used to be the dirty little secret of the USB drive industry was how hard it was (is?) to find the read/write speeds on every drive. Sometimes two different brand drives which are otherwise identical have radically different read and write capabilities. Sometimes for just about the same price you can get a drive that's 3 times or more faster than its competitors.

I just spent a couple of weeks trying to pick out a flash drive due to this very thing.  The online store tech specs blurb often doesn't even have the write speed listed.  Checking out benchmarks you find what is supposed to be a good ratio of write speed per dollar then find out from user reviews, once delivered the drive doesn't actually write at that speed for sustained writes.

I ended up with a Verbatim Store & Go which has pretty good sequential write speed, but I'm just wondering how it will stand up to constant plugging/unplugging since it has a plastic slide inside a really flimsy plastic sleeve.

Seems like instead of devices these things are still considered throw-away gimmicks or stocking stuffers.  Kind of like a ball point pen.  Most of these 16 GB or larger are coming in at over $50.  Time there should be some meaningful stats to go with them.  Like sequential read/write speed and durability info(will the thing break the 11th time you unplug it?)

Serious reviews should contain "life testing" results where an automaton plugs/unplugs the thing with a counter to give the average fail count.  Great if something writes at 20 MB/sec. but not so great if it splits in 2 the 3rd time you unplug it.

« Last Edit: December 28, 2009, 11:51:50 AM by MilesAhead » Logged

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shobazi
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« Reply #10 on: January 02, 2010, 06:54:24 PM »

It's Really a good advice.Till now  I never heard anything about fake USB sticks..I try out this
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