Anyway to make monuting do fsck before mounting? Shall I edit fstab command line or ?
On Thu, Mar 27, 2014 at 11:22 AM, Yiling Cao <yiling....@gmail.com> wrote: > Thanks Brandon for your experience. I do agree with that better to put > whole disk read only. > > But how do iPhone and Android survive? Esp for those Android phones? They > are very prone to sudden power removal as well. > > How do routers handle this issue? they save the settings on different > devices? > > I have a SQLite db around 1-2M and data will be written to them. Would > like to have some easy and quick solution to make it absolutely stable. > > > > On Thu, Mar 27, 2014 at 9:46 AM, Brandon I <brandon.ir...@gmail.com>wrote: > >> Here's a good read: >> http://www.embeddedarm.com/about/resource.php?item=459 >> >> I had a loooooooong discussion about this with a colleague of mine after >> we started seeing boards die. >> >> Basically you're eventually doomed unless you mount the whole disk as >> read only since the wear leveling algorithms in the flash have no knowledge >> of what a partition is and will eventually end up with >> suppesed-to-be-read-only data mixed in with the writable partition erase >> blocks. If you're writing to flash, it will eventually fail by unfortunate >> design. >> >> It tooks his previous company 6 months of fighting to come to terms with >> this in their last product. They had to write data, so eventually used usb >> flash that the customer could easily replace when things eventually died. >> They tried every flash card they could get their hands on, read only >> partitions, etc and eventually had to give up. >> >> Use the SD card you say! Any micro SD card you can put in the slot is >> absolutely not meant for continuous writing. The SD card spec has a very >> specific use case in mind (video and images), and logging or using it as a >> sparse write file system goes completely against the intended SD card >> design specs. Industrial grade write-tolerant flash will cost you hundreds >> of dollars more than something on Amazon. >> >> With our current product, I told my boss that I was worried about >> corruption and that we would eventually go to read only once we debugged >> the boards. Within two weeks of only log messages, all of our boards >> started dyeing. The next day, all disks were mounted as read only and >> issues are debugged with the in-memory log files. We haven't seen any >> failures in 6 months now. >> >> The easy solution is trying to force the answer of "why are you writing >> anything to persistent storage?" to be "there's no good reason since it >> eventually bricks our product". If you want something that will last >> forever, you will not write to standard flash media. If you can't, then >> maybe use a usb flash drive (MUCH better life than a micro sd card) and >> count the days until it corrupts or someone pulls the power at an >> inopportune time. You could always use a battery backup to get rid of the >> power off issue. :-\ >> >> This is all doom and gloom, but it's a consequence of inconsistent power, >> buffers, and the destruction nature of quantum tunneling. >> >> -Brandon >> >> On Wednesday, March 26, 2014 2:45:57 PM UTC-7, Sungjin Chun wrote: >> >>> How about making system partition be mounted as read-only and data >>> partition be mounted after booting and checking? In this case, only data >>> partition has possibility of corruption. >>> >>> Sent from my iPad >>> >>> On Mar 26, 2014, at 9:53 PM, Yiling Cao <yilin...@gmail.com> wrote: >>> >>> Hi I have some my products deployed with am335x with Micron eMMC 2GB, >>> but my products allow users to unplug power as they wish. >>> >>> My linux app very rarely writes to the eMMC. and my /etc/fstab specifies >>> /var/log and /tmp to tempfs; fstab mount all partitions with "noatime" >>> properties. >>> >>> But around 2 months of deployment, I found that around 1-2% am335x >>> machines, have some sort of data corruption, resulting fail to boot up. >>> >>> Can anyone share some thoughts/ experience about how to resolve this >>> issue? In real life product, whats the best practice? >>> >>> -- >>> 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. >>> >>> 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. 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