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

[Francisco Ares]

2013/9/3 <meino.cramer@×××.de>

> Francisco Ares <frares@×××××.com> [13-09-04 02:08]:
> > Em 03/09/2013 13:12, <meino.cramer@×××.de> escreveu:
> > >
> > > William Kenworthy <billk@×××××××××.au> [13-09-03 17:16]:
> > > > On 03/09/13 11:26, meino.cramer@×××.de wrote:
> > > > > William Kenworthy <billk@×××××××××.au> [13-09-03 05:08]:
> > > > >> On 03/09/13 10:45, meino.cramer@×××.de wrote:
> > > > >>> walt <w41ter@×××××.com> [13-09-03 04:15]:
> > > > >>>> On 09/02/2013 09:15 AM, meino.cramer@×××.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
> > >
> > >
> > >
> >
> > There are some parameters for creating a better backup archive using tar,
> > like --same-owner and --atime- preserve.
> >
> > By the way, it would be an interesting project to export some folders on
> > your home computer using nfs, tuneling it through ssh, monting it locally
> > in your embedded computer, and applying an unionfs to the rootfs.  Just
> > dreaming, of course.
> >
> > Góod luck
> > Francisco
>
> Hi Francisco,
>
> as I understand the man page, --same-owner is only activ while
> extracting a tar:
>
>      --same-owner
>               create extracted files with the same ownership
>
> while extracting I always use
>
>       --preserve
>               like --preserve-permissions plus --same-order
>
> . Atime setting is disabled via fstab on my embedded system for two
> reasons:
> Performance wise since any access to a file will trigger a write
> action to the flash chip even when reading the file.
> Any write action to a flash chip wear out the chip -- it has a limited
> number of write cycles.
> I also disbaled atime on my PC for the first reason.
>
> What makes the unionfs'ed nfs mount of my PC on the embedded system
> interesting to you ?
> (sorry if this question sounds bad/negative/... or so...its my limited
> english. Its simply and only a question and the wish of getting more
> infos... :)
>
> Best regards,
> mcc
>
>
>
>
>
>
Hi, Meino.

Sorry for my delay in answering your message. Sorry for my english, too, as
a non-native speaker, I know sometimes I may sound strange.

I am (trying to) finishing an embedded equipment, using an Intel x64, and
Gentoo Linux. The main file system will be stored in a SATA "disk on
module" flash device, but there are some directories that are not needed
for daily use, or should not be present at all on the final product, like
private source code used to build the program that run this equipment.

So on the development system, I have used several disk partitions (as a
first approach) for this directories, like /usr/portage , /usr/src ,
/usr/include and so on, and I was thinking on a way of remote access, so
that a remote system could use the structure of this local development
system. So I suppose that some unionfs mounts would make things appear
local to the remote system. But probably just nfs would do the trick. As I
said, just dreaming.

And what about your problem?

Best regards,
Francisco