Re: [gentoo-user] Re: Need help: Filesystem (ext4) corrupted!

[meino.cramer@gmx.de]

William Kenworthy <billk@iinet.net.au> [13-09-03 05:08]:
> On 03/09/13 10:45, meino.cramer@gmx.de wrote:
> > walt <w41ter@gmail.com> [13-09-03 04:15]:
> >> On 09/02/2013 09:15 AM, meino.cramer@gmx.de wrote:
> >>> The rootfs and $HOME of my embedded system is stored 
> >>> on a 16GB SD-card (about 5GB used, rest free). The FS
> >>> is ext4.
> >>>
> >>> Since the system hangs for unknown reasons several times
> >> Does it hang at a predictable point, like during boot, or poweroff?
> >>
> >> I know almost nothing about SD cards (yet).  Do they develop bad
> >> blocks like other storage media?  I notice fsck.ext4 has a -c flag
> >> to check for bad blocks.  
> >>
> > No, it hangs while compiling or while updateing (eix-sync; emerge ...).
> >
> >
> > I did the following now:
> > I did a binary image backup with dd of the sdcard.
> > I made a backup of the all files from the bad fs with tar.
> > I say "YES" to fsck to fix what it found.
> > I made another backup of the all files from the bad fs with tar.
> > I md5summed both tar archives and found them identical.
> >
> > Now...is the conclusion correct, that the identical md5sum
> > indicate, that the fixed error of the fs only had impact to
> > already invalidated data?
> > Or whatelse could this indicate?
> >
> > Best regards,
> > mcc
> >
> > PS: What come mind just in this moment:
> > Can I ran fsck on an binary image of the fs which I made with dd somehow?
> >
> >
> >
> >
> >
> 
> Have you run out of inodes? - ext 4 has had very mixed success for me on
> solid state.  Running out of inodes is a real problem for gentoo on
> smaller SD cards with standard settings.
> 
> BillK
> 
> 
> 

Does this error message from fsck indicate that? I am really bad in
guessing what fsck tries to cry at me ... ;)


> >     solfire:/root>fsck.ext4 -f -p /dev/sdb2
> >     rootfs: Inodes that were part of a corrupted orphan linked list found.
> >
> >     rootfs: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
> >         (i.e., without -a or -p options)
> >     [1]    18644 exit 4     fsck.ext4 -f -p /dev/sdb2
> >
> >

Is there any way to correct the settings from the default values to
more advances ones, which respect the sdcard size of 16GB *without*
blanking it...a "correction on the fly" so to say???

And if not: Is there a way to backup the sdcard and playback the files
after reformatting it by preserving all three time stamps of the
files (atime is deactivated via fstab though) ?

Best regards,
mcc