On Wed, Jul 20, 2016 at 9:23 AM, Ankur Tank <artf...@gmail.com> wrote:
> > We have BBB based custom board with 256MB RAM and 4GB eMMC running Linux > kernel 3.12 > > *TL;DR*: Is there a open source application which periodically reads > unread/rarely used partition to increase data retention? OR Is there any > kernel service which can be configure > > *Detailed query,* > We have 3 sets of partition for OS(Bootloader, kernel+dtb & RFS) eMMC. > One of them is recovery OS. Which is rarely read( none of the time > written). > > Now as per eMMC manufacturerer, > "*If a byte is not read in 5 years there is no guarantee that byte is > valid when read after 5 years.*" > To avoid such situation we want to have a crawler application, which would > read all the unused/unread partition may be once in a year and increase > data retention. > > I didn't find any open source application or kernel service/daemon which > would handle that. But not sure If I am searching it correctly or not. > > Meanwhile If there is no solution available for this, I am planning to do > it in following way. > > 1. Setup a cron job which would trigger once in a year and run a script. > 2. Script would read all the partition using dd and return. > > What do you think about this approach. > Let me know if you have any suggestion/correction/pointers for me. > debian@test-bbb-1:~$ time sudo cat /dev/mmcblk1 > /dev/null real 1m20.209s user 0m0.050s sys 0m14.530s That was for a 2GB eMMC, so double the time for a 4GB.. But in reality, with eMMC, we are still only talking with the controller, not directly with the NAND. So even a cat won't read every 'byte' as the controller is doing it's own thing... Regards, -- Robert Nelson https://rcn-ee.com/ -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAOCHtYi7%3DKeg7Le%2Bd066OXhscNwj10Mee9-yZbXanjb%2BYZgKrQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
