From: Curt Carpenter <1cjcarpen...@att.net> Reply-To: "beagleboard@googlegroups.com" <beagleboard@googlegroups.com> Date: Friday, October 31, 2014 at 3:22 PM To: "beagleboard@googlegroups.com" <beagleboard@googlegroups.com> Subject: Re: [beagleboard] Should I Boot From SD Card?
> Thanks John. I've read the two articles. > > I have no idea of the endurance of my SD card, but it seems that I will be > better off using it as the boot device in a development environment as it can > be replaced when the time comes, where as the eMMC can't, and development > involves a lot of file creation and deletion over time, at least the way I do > it :-) Does that sound right to you? > > I guess I need to design and build my software too so that it minimizes file > I/O. Is that standard practice for linux programs that I might download with > apt-get, or are there some that I should avoid for that reason? To start with, you should try to use a read only rootfs. Search beagleboard groups as this has been discussed several times. In addition, if your app involves some sort of data acquisition or data logging, use ram based files and then only write the contents to disk on a periodic bases or when the power fails. This means you need circuitry to detect the power fail and then trigger writing all ram based files to disk and then start an orderly shutdown. Traditionally, this is done with a temporary energy source from supercaps or batteries. The circuit requires a state machine to cater for situations such as power fails during power up, or power fails and then returns before shutdown is complete. > > > I don't know what The Deck is John, but I doubt if I'll ever need 12 GB. I > just happened to have a 16 laying around from another project. Hard to > imagine a 12GB app on a board this small :-) The Deck is a wireless penetration suite developed by Philip Polstra. Regards, John > > > Thanks for the inputs/ > > > On Friday, October 31, 2014 2:06:46 PM UTC-5, john3909 wrote: >> The answer is it depends on the SDCard you are using. Compare the number of >> write cycles for your SDCard to that of the eMMC. If the number of write >> cycles is the same for both devices, the eMMC will fail first because of the >> smaller spare capacity given the use of wear leveling. To reduce the >> possibility of write failure, increase the size of your storage. >> >> http://en.wikipedia.org/wiki/Flash_memory >> http://en.wikipedia.org/wiki/Wear_leveling >> >> Regards, >> John >>> >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to beagleboard...@googlegroups.com <javascript:> . >>> For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
