I've got a 512MB USB flash keychain. Tonight I tried to use it and it didn't work. Ack! So, after some cleaning of contacts and messing around I got it to be recognized on my Mac mini, but with no filesystem. I dd'd the contents to a .iso file so I'd at least have some sort of backup. As it stands, the backup file is smaller than it should be (480MB?) so I'm not too confident in it. Anyway, can anyoe suggest a recovery tool for the drive itself, or to process a block dump? Either Mac OS or Linux tools would be good. I'm fairly sure it was in FAT32. So far Googling tends to bring up demos and trial ware.
On Thursday 15 March 2007 02:22:05 am Jon Pruente wrote:
As it stands, the backup file is smaller than it should be (480MB?) so I'm not too confident in it.
That's probably just the classic false advertising.
500,000,000 bytes (sold as "500 MB") is approximately 477 MB 512,000,000 bytes (sold as "512 MB", even more misleading) is approx 488 MB
Nothing false about it. It's the inevitable result of using an established term to mean something different.
The SI prefix 'M' means 10^6, not 2^20. Memory is almost always listed using the binary terminology, which would be written MiB according to the most popular disambiguation scheme. HD manufacturers all use the SI meaning, because it allows them to advertise a larger number of MB. A third definition of 'MB' is that used by floppy drives, 10^3 x 2^10, or 2000 sectors of 512 bytes. A '1.44 MB' floppy has 2880 sectors.
On 3/14/07, Luke-Jr [email protected] wrote:
That's probably just the classic false advertising.
500,000,000 bytes (sold as "500 MB") is approximately 477 MB 512,000,000 bytes (sold as "512 MB", even more misleading) is approx 488 MB
On Thursday 15 March 2007 12:37, Monty J. Harder wrote:
Nothing false about it. It's the inevitable result of using an established term to mean something different.
"using an established term to mean something different" is dishonest/false. :p
The SI prefix 'M' means 10^6, not 2^20.
I don't see any legitimacy to a claim over a single-letter abbreviation. Can I claim 'L' and prevent anyone from making any abbreviation beginning with that letter? :)
Memory is almost always listed using the binary terminology, which would be written MiB according to the most popular disambiguation scheme.
Only SI proponents use MiB from what I've seen.
HD manufacturers all use the SI meaning, because it allows them to advertise a larger number of MB.
Exactly. False advertising.
A third definition of 'MB' is that used by floppy drives, 10^3 x 2^10, or 2000 sectors of 512 bytes. A '1.44 MB' floppy has 2880 sectors.
IIRC, that was an accident.
Its not false advertising, they are just following IEC and IEEE standards. The IEC realized that people were incorrectly using SI prefixes to denote quantities of binary numbers. That's why in 1999 the IEC introduced the prefixes kibi, mebi, gibi, etc. to specify multiples of a binary quanity. So, in reality, its us who are still using incorrect notations. Hardware manufactures stick to the IEEE standards. So it's the engineers, not the marketing and sales people who are responsible.
477MiB = 500,170,752 bytes = 500MB
However, once something gets stuck in someone's head, it hard to change. Take the metric system as an example. Its a far better system of measurement than the old standard, but people here in the US still thumb their noses at it. I'm like you and I too get that confused, because that's how I learned it way back when. Hopefully they are teaching the next generation the correct notations so a few generations from now this will all be interesting geek trivia.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Luke -Jr Sent: Thursday, March 15, 2007 12:53 PM To: Monty J. Harder Cc: [email protected] Subject: Re: USB flash recovery tools?
On Thursday 15 March 2007 12:37, Monty J. Harder wrote:
Nothing false about it. It's the inevitable result of using an established term to mean something different.
"using an established term to mean something different" is dishonest/false. :p
The SI prefix 'M' means 10^6, not 2^20.
I don't see any legitimacy to a claim over a single-letter abbreviation. Can I claim 'L' and prevent anyone from making any abbreviation beginning with that letter? :)
Memory is almost always listed using the binary terminology, which would be written MiB according to the most popular disambiguation
scheme.
Only SI proponents use MiB from what I've seen.
HD manufacturers all use the SI meaning, because it allows them to advertise a larger number of MB.
Exactly. False advertising.
A third definition of 'MB' is that used by floppy drives, 10^3 x 2^10,
or 2000 sectors of 512 bytes. A '1.44 MB' floppy has 2880 sectors.
IIRC, that was an accident. _______________________________________________ Kclug mailing list [email protected] http://kclug.org/mailman/listinfo/kclug
On Thursday 15 March 2007 13:47, you wrote:
However, once something gets stuck in someone's head, it hard to change. Take the metric system as an example. Its a far better system of measurement than the old standard, but people here in the US still thumb their noses at it. I'm like you and I too get that confused, because that's how I learned it way back when. Hopefully they are teaching the next generation the correct notations so a few generations from now this will all be interesting geek trivia.
I reject SI byte units *because* they are SI/metric, not just because I'm used to the original units.
Decimal is annoying. If we're going to fix units, they should be based off binary or hexadecimal. At least here in the US we have binary measurements for liquids (1 peck = 2 gallons = 4 pottles = 8 quarts = 16 pints = 32 cups = 64 gills)
Instead of base 10 or base 2 we should choose something really universal, like base e.
Luke -Jr [email protected] wrote: Decimal is annoying. If we're going to fix units, they should be based off binary or hexadecimal.
1 US peck = 2.32729448 US gallons... http://www.google.com/search?hl=en&q=peck+in+gallons&btnG=Google+Sea...
-----Original Message----- From: Luke -Jr [mailto:[email protected]] Sent: Thursday, March 15, 2007 2:02 PM To: Jeremy Fowler; [email protected] Subject: Re: USB flash recovery tools?
On Thursday 15 March 2007 13:47, you wrote:
However, once something gets stuck in someone's head, it hard to
change.
Take the metric system as an example. Its a far better system of measurement than the old standard, but people here in the US still thumb their noses at it. I'm like you and I too get that confused, because that's how I learned it way back when. Hopefully they are teaching the next generation the correct notations so a few generations from now this will all be interesting geek trivia.
I reject SI byte units *because* they are SI/metric, not just because I'm used to the original units.
Decimal is annoying. If we're going to fix units, they should be based off binary or hexadecimal. At least here in the US we have binary measurements for liquids (1 peck = 2 gallons = 4 pottles = 8 quarts = 16 pints = 32 cups = 64 gills)
On Thu, Mar 15, 2007 at 02:22:37PM -0500, Jeremy Fowler wrote:
On : Thursday, March 15, 2007 2:02 PM Luke -Jr wrote:
Decimal is annoying. If we're going to fix units, they should be based off binary or hexadecimal. At least here in the US we have binary measurements for liquids (1 peck = 2 gallons = 4 pottles = 8 quarts = 16 pints = 32 cups = 64 gills)
1 US peck = 2.32729448 US gallons... http://www.google.com/search?hl=en&q=peck+in+gallons&btnG=Google+Sea...
1 US peck == 2.32729448 US (wet) gallons. 1 US peck == 2 US (dry) gallons.
Source Wikipedia http://en.wikipedia.org/wiki/U.S._customary_unit#Liquid_volume http://en.wikipedia.org/wiki/U.S._customary_unit#Dry_volume
As a child in school we laid out a kilometer as 1000 meters. Were we off by 24 meters? I think not.
-- Hal Duston [email protected]
Only SI proponents use MiB from what I've seen.
Only scientists, engineers, and people who want to retain the existing definition, which was codified as an international standard long before computer geeks noticed that 2^10 is a tad more than 10^3, and copied the 'kilo' prefix FROM SI.
When I'm bitching about people butchering English, I draw a distinction between new words, or old words gaining additional meanings that don't contradict the old meanings; and the corrosive effect of a new meaning that opposes an existing meaning.
One of my peeves is people using a word like 'comprise' to mean the opposite of what the word traditionally has meant. This threatens to make the word meaningless.
When there's already an established meaning of SI prefixes, people deliberately misuse those prefixes to mean something else, and then have the gall to say that people who are using them as actual SI prefixes are 'false', we've gone through the looking glass and are having tea with the Queen, the Mad Hatter, and Humpty Dumpty.
HD manufacturers all use the SI meaning, because it allows them to advertise a larger number of MB.
Exactly. False advertising.
No, it would be suicidal for an HD manufacturer to use your definition of MB or GB, because it would make their drives look more expensive than competitors' drives of the same nominal size. There is nothing false about using the M and G prefixes in accordance with international standards.
It reminds me of a David Cross bit where he criticized people for using the word "literally" incorrectly. Funny stuff.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Monty J. Harder Sent: Thursday, March 15, 2007 2:05 PM To: Luke -Jr Cc: [email protected] Subject: Re: USB flash recovery tools?
One of my peeves is people using a word like 'comprise' to mean the opposite of what the word traditionally has meant. This threatens to make the word meaningless.
To clarify due to the extended discussion here, the file that dd wrote is 503709696 bytes on both machines.
Jon.
On 3/14/07, Jon Pruente [email protected] wrote:
I've got a 512MB USB flash keychain. Tonight I tried to use it and it didn't work. Ack! So, after some cleaning of contacts and messing around I got it to be recognized on my Mac mini, but with no filesystem. I dd'd the contents to a .iso file so I'd at least have some sort of backup. As it stands, the backup file is smaller than it should be (480MB?) so I'm not too confident in it. Anyway, can anyoe suggest a recovery tool for the drive itself, or to process a block dump? Either Mac OS or Linux tools would be good. I'm fairly sure it was in FAT32. So far Googling tends to bring up demos and trial ware.
On Wed, Mar 14, 2007 at 09:22:05PM -0500, Jon Pruente wrote:
I've got a 512MB USB flash keychain. Tonight I tried to use it and it didn't work. Ack! So, after some cleaning of contacts and messing around I got it to be recognized on my Mac mini, but with no filesystem. I dd'd the contents to a .iso file so I'd at least have some sort of backup. As it stands, the backup file is smaller than it should be (480MB?) so I'm not too confident in it. Anyway, can anyoe suggest a recovery tool for the drive itself, or to process a block dump? Either Mac OS or Linux tools would be good. I'm fairly sure it was in FAT32. So far Googling tends to bring up demos and trial ware. _______________________________________________ Kclug mailing list [email protected] http://kclug.org/mailman/listinfo/kclug
I would copy your backup and start playing around with it. Have you tried yet to mount it as a loopback device? Does fsck do anything to it?
Recovered! I spent some time plugging and unplugging it, and cracked the case and pressed and poked at all the components. Finally several tries later it recognized, and actually mounted a filesystem. I immediately opened a Terminal window and dd'd a copy of the entire device. It gave me the same file size as the other copies, but this one had readable files on it. When that was done I tried browsing the drive and the files I checked out opened ok. Then I mounted the last image I made with dd, which I had named with a .iso extension, and it mounted fine and the files were available there. SO, I unmounted the drive and un- and re-plugged it. It didn't mount. I did it again and it mounted. Unmount and tried again, no mount - and it hasn't since.
At least I had that small cahnce to make a good copy of the device.
Jon.
On 3/16/07, Kyle Sexton [email protected] wrote:
I would copy your backup and start playing around with it. Have you tried yet to mount it as a loopback device? Does fsck do anything to it?
-- Kyle Sexton
On 3/16/07, Jon Pruente [email protected] wrote:
At least I had that small cahnce to make a good copy of the device.
and re-learn the lesson that if only have a file on one device, you may not have it for long.
If it's important, back it up. Micro Center has 1 GB (SI, not binary) flash drives for under $10, and 2 GB for a few bucks more. Make at least two copies of everything, and store them separately. Or attach a copy to an email and send it to your Gmail account....
On Fri, Mar 16, 2007 at 10:44:19PM -0500, Jonathan Hutchins wrote:
On Friday 16 March 2007 09:04:03 pm Monty J. Harder wrote:
Make at least two copies of everything, and store them separately. Or attach a copy to an email and send it to your Gmail account....
Better yet, send a copy to everyone in your address book, just like a spam email!
Kclug mailing list [email protected] http://kclug.org/mailman/listinfo/kclug
Only wimps use tape backup: _real_ men just upload their important stuff on ftp, and let the rest of the world mirror it ;)
* Torvalds, Linus (1996-07-20).
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Hal Duston -
James Sissel -
Jeremy Fowler -
Jon Pruente -
Jonathan Hutchins -
Kyle Sexton -
Luke -Jr -
Luke-Jr
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Monty J. Harder