Sure, but that doesn't help you with what you were in the middle of writing.
Look under disadvantages for both : http://en.wikipedia.org/wiki/Ext3 http://en.wikipedia.org/wiki/Ext4 Wikipedia has been know to be wrong, but those both have the potential for issues, however small the %, in the event of power loss or system crash while the file isn't finished being written. You will also shorten the life expectancy of your SD card using a journaling filesystem, as it will incur the extra writes of the journal. I'm not saying don't use a journaling filesystem, just stating that it's not 100% fail safe. The safest option would be to add a UPS that can give you warning that the power is out and enough time to ensure you don't have any files open, but preferably do a shutdown. Outside of that don't keep files open any longer than you need to. Cheers, Aaron On 25 June 2010 16:32, Maxim Podbereznyy <[email protected]> wrote: > if your writing in a middle and power goes off, then the journal won't be > updated and you will never find this file. So all previous writes are > correct. > > 2010/6/25 Kamondelious <[email protected]> > > > Is adding in hardware/UPS a possible option? > > > > There is some small stuff out there : > > http://www.mini-box.com/micro-UPS-load-sharing > > > > You wouldn't need anything that lasts very long, just enough time to make > > sure you don't have any files open. Maybe even issue a shutdown from > your > > application. > > > > A journalling filesystem can't give you a 100% guarantee against file > > corruption, if you're in the middle of writing a file and the power goes > > out, there's a good chance that file will have issues. > > > > If hardware/UPS isn't an option, then your safest bet would be to only > have > > a file open when you absolutely need it open and close it as soon as > > possible. The downside is you will incur more processing overhead as you > > open/close files more often than you might normally. > > > > Hope any of this helps. > > > > Cheers > > > > Aaron > > > > > > On 25 June 2010 15:26, Maxim Podbereznyy <[email protected]> wrote: > > > > > why don't you use journaling file system? They are specially invented > to > > > increase stability on instable systems > > > > > > 2010/6/25 Chris <[email protected]> > > > > > > > Hi, > > > > > > > > This is when power is cut. Not by some guy or by anything that I > > manage. > > > > Unfortunately - in this application, power must be cut fairly > > regularly. > > > > > > > > The idea has developed a bit since my last email. > > > > I am thinking of using a union file system for Angstrom with only the > > > home > > > > directory writeable located on a NAND chip. > > > > I am be constantly saving data to a separate SD card with a FAT32 > file > > > > system - which I am worried will become corrupted when the hard reset > > > > occurs. > > > > > > > > What safeguards can I put in place to protect this? > > > > > > > > Cheers, > > > > Chris > > > > > > > > > > > > On 21/06/10 22:00, [email protected]: > > > > > > > >> Message: 1 > > > >> Date: Sun, 20 Jun 2010 16:48:02 +0400 > > > >> From: Maxim Podbereznyy<[email protected]> > > > >> Subject: Re: [Angstrom-distro-users] Hard resets > > > >> To:[email protected]<to%[email protected]> > <to%[email protected]<to%[email protected]> > > > > <to%[email protected]<to%[email protected]> > <to%[email protected]<to%[email protected]> > > > > > > > > <to%[email protected]<to%[email protected]> > <to%[email protected]<to%[email protected]> > > > > <to%[email protected]<to%[email protected]> > <to%[email protected]<to%[email protected]> > > > > > > > > > > > > >> Message-ID: > > > >> < > [email protected]> > > > >> Content-Type: text/plain; charset=ISO-8859-1 > > > >> > > > >> What do you mean by hw-reset? Is it performed by some guy or you > > manage > > > >> some > > > >> power switch? > > > >> > > > >> 2010/6/19 Chris<[email protected]> > > > >> > > > >> > > > >> > > > >>> > Hi Max, > > > >>> > > > > >>> > Thanks for the info! > > > >>> > > > > >>> > So should I put that code after every write? > > > >>> > Obviously I am not sure when the reset will occur - so that will > > > >>> provide > > > >>> > most protection? > > > >>> > > > > >>> > Cheers, > > > >>> > CJ > > > >>> > > > > >>> > > > > >>> > > > > >>> > Chris, > > > >>> > > > >>> > > > >>>> >> > > > >>>> >> what if you perform syncing before hard reset? > > > >>>> >> > > > >>>> >> insert in your code: > > > >>>> >> > > > >>>> >> sync(); > > > >>>> >> hw_reset(); > > > >>>> >> > > > >>>> >> regards, > > > >>>> >> Max > > > >>>> >> > > > >>>> >> 2010/6/18 Chris<[email protected]> > > > >>>> >> > > > >>>> >> > > > >>>> >> > > > >>>> > > > >>>> > > > >>>>> >>> Hi, > > > >>>>> >>> > > > >>>>> >>> I have an application where there will be many hard resets > > > often. > > > >>>>> >>> I am using EXT3 as my file system - and there are problems > > with > > > >>>>> system > > > >>>>> >>> integrity because of the resets. > > > >>>>> >>> > > > >>>>> >>> When I was using an x86 board I worked with a debian based > > > distro > > > >>>>> that > > > >>>>> >>> allowed me to boot and run the OS from ram. > > > >>>>> >>> This was a good solution as the media was never mounted. > > > >>>>> >>> > > > >>>>> >>> Has anyone done this with Angstrom? > > > >>>>> >>> Any other ideas to solve this problem? > > > >>>>> >>> > > > >>>>> >>> Cheers, > > > >>>>> >>> CJ > > > >>>>> >>> > > > >>>>> >>> _______________________________________________ > > > >>>>> >>> Angstrom-distro-users mailing list > > > >>>>> >>> [email protected] > > > >>>>> >>> > > > >>>>> > > > > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > >>>>> >>> > > > >>>>> >>> > > > >>>>> >>> > > > >>>>> > > > >>>>> > > > >>>> >> > > > >>>> > > > >>>> > > > >>> > > > > >>> > _______________________________________________ > > > >>> > Angstrom-distro-users mailing list > > > >>> > [email protected] > > > >>> > > > > >>> > > > > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > >>> > > > > >>> > > > >>> > > > >> ------------------------------ > > > >> > > > >> Message: 2 > > > >> Date: Sun, 20 Jun 2010 19:21:46 +0200 > > > >> From: "Przemek Zielony"<[email protected]> > > > >> Subject: [Angstrom-distro-users] SQLite and php5 > > > >> To:<[email protected]> > > > >> Message-ID:<000701cb109d$10808880$9101a...@toshiba> > > > >> Content-Type: text/plain; format=flowed; charset="iso-8859-2"; > > > >> reply-type=original > > > >> > > > >> I would like to install php5 and SQLite on SAM9261 board with linux > > > >> Angstrom. I'm really newbie and I have some problem with it. Should > I > > > use > > > >> ipkg? If not, how to do it? > > > >> > > > >> Cheers, > > > >> PZ > > > >> > > > >> > > > >> > > > >> > > > >> ------------------------------ > > > >> > > > >> _______________________________________________ > > > >> Angstrom-distro-users mailing list > > > >> [email protected] > > > >> > > > > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > >> > > > >> > > > >> End of Angstrom-distro-users Digest, Vol 45, Issue 15 > > > >> ***************************************************** > > > >> > > > >> > > > >> > > > > > > > > > > > > _______________________________________________ > > > > Angstrom-distro-users mailing list > > > > [email protected] > > > > > > > > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > > > > > _______________________________________________ > > > Angstrom-distro-users mailing list > > > [email protected] > > > > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > > > _______________________________________________ > > Angstrom-distro-users mailing list > > [email protected] > > > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > > > _______________________________________________ > Angstrom-distro-users mailing list > [email protected] > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users > _______________________________________________ Angstrom-distro-users mailing list [email protected] http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/angstrom-distro-users
