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

[meino.cramer@gmx.de]

William Kenworthy <billk@iinet.net.au> [13-09-03 17:16]:
> On 03/09/13 11:26, meino.cramer@gmx.de wrote:
> > 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
> >
> >
> >
> >
> >
> df -i - if you get 100% iUSE or near to it thats your problem ... I have
> seen that error message you give as a result of running out of inodes
> corrupting the FS.
> 
> No, your only way out is to copy (I use rync) the files off, recreate
> the fs with max inodes ("man mke2fs") and rsync the files back.  Once an
> ext* fs has been created with a certain number of inodes its fixed until
> you re-format.
> 
> I get it happening regularly on 4G cards when I forget and just emerge a
> couple of packages without cleaning up in between packages.  On 16G
> cards, its compiling something like glibc or gcc that uses huge numbers
> of inodes at times.  On a single 32G card I have, the standard settings
> have been fine ... so far :)
> 
> Billk
> 
> 

df -i gives the following:

rootfs           971040 352208   618832   37% /
/dev/root        971040 352208   618832   37% /
devtmpfs          63420    434    62986    1% /dev
tmpfs             63456    389    63067    1% /run
shm               63456      1    63455    1% /dev/shm
cgroup_root       63456      6    63450    1% /sys/fs/cgroup
/dev/mmcblk0p1        0      0        0     - /boot


You mentioned rsync to backup...

I used 

    sudo tar cvf <backup file> <root of embedded system>

the rootfs has only one partition...

Is it alos ok to use tar or is there any drawback....?

Best regards,
mcc