On 4/23/2013 9:35 PM, Jon Elson wrote: > Jon Elson wrote: >> Ralph Stirling wrote: >> >>> One show stopper I found with the RPi was the high probability >>> of SD card corruption during power cycles (power failure without >>> full OS shutdown first). Is the BeagleBone Black immune to this >>> problem? The quoted ten second shutdown is good, but I'd like >>> to have the flash image survive unforeseen power failures. If >>> it handles those fine, then I'm ready to get excited about it. >>> >>> >> This is a problem that has been around for some time. it is almost >> certainly more >> complicated than at first glance. > Oh, one other data point. I have been using SanDisk 4gb SD cards, with > relatively > few problems. I have a Dane-Elec disk that croaked after minimal usage, and > doesn't seem to be repaired by fsck. A number of other users also > report good > luck with official SanDisk and some other name-brand cards, and a lot > of problems with off-brand or cards that might be counterfeit, bought on > eBay or whatever. I bought many of my SD cards at MicroCenter. > > If the power is shut off while the SD card is in the middle of a > wear-leveling > swap, I don't know how it will handle that. There are methods of keeping > all data in a secure condition until the swap is complete, but some cheap > controllers may not have firmware that does this right. If the > wear-leveling > remap table gets corrupted, the card is generally scrap, there's no way to > reformat it. >
I remember having problems with my brand new BeagleBoardXM not booting Arch Linux from specific microSD cards, instead throwing an mmc time-out error. The first one to fail was a SanDisk card with proper specifications but the problem seemed to be a function of manufacturing tolerance or some other hidden variable and not of the specific manufacturer. There was lots of forum traffic (stretching back to 2009!), lots of handwaving and kernel developers kept adding defensive code to the driver and suggesting different kernel configuration parameters. The offending cards seemed to work with other distributions including the Angstrom distribution of the time. As I said in a Feb 2012 ArchLinux forum message, "there doesn't seem to be any consistency to the implementations of the fixes in various distributions." The offending cards also seemed to work with other boards which suggested to me the problem may be exacerbated by the nature of the BeagleBoardXM's physical interface to the microSD card. I never felt comfortable with microSD card technology after that. The rampant counterfeiting doesn't help either---but that wasn't the source of my problem. I'm not reading all the forums I used to and this problem you're discussing has caught me completely by surprise. It makes me even more uncomfortable. I wonder if the built-in flash memory of the new BeagleBone Black can have this problem too? That would be a nasty surprise. Regards, Kent ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
