Tomas Pospisek | 25 May 23:59 2015

fsck failing to notice that the block device was pulled out from under it?


tl;dr: it seems like fsck fails to notice when the block device
disappears from under it.

I have the following setup:

* external USB disk
* a partition with LUKS in it
* ext4 filesystem inside the LUKS block device

While doing backups to it I noticed that after some time backups would
fail with an error (failed to write, ).

In the following log I'm attaching the disk, enabling LUKS and mounting
the disk and then starting the backup, which will fail after a while:

May 25 11:39:18 hier kernel: [76241.727367] usb 4-1.1: new high-speed
USB device number 6 using ehci-pci
May 25 11:39:19 hier kernel: [76241.881892] usb 4-1.1: New USB device
found, idVendor=0bc2, idProduct=3320
May 25 11:39:19 hier kernel: [76241.881902] usb 4-1.1: New USB device
strings: Mfr=2, Product=3, SerialNumber=1
May 25 11:39:19 hier kernel: [76241.881907] usb 4-1.1: Product:
Expansion Desk
May 25 11:39:19 hier kernel: [76241.881911] usb 4-1.1: Manufacturer: Seagate
May 25 11:39:19 hier kernel: [76241.881915] usb 4-1.1: SerialNumber:
May 25 11:39:19 hier kernel: [76241.882652] usb-storage 4-1.1:1.0: USB
Mass Storage device detected
(Continue reading)

Rogier Wolff | 4 Feb 13:57 2015

block group descriptors.


A friend of mine managed to corrupt his block group descriptor
table. When starting e2fsck, it says that it is corrupt and will use
the backup. Great!

However, will e2fsck be able to fix this, or will I have to do this
manually? The FSCK is still running, expected to finish "pass 1" in
about four hours.



** R.E.Wolff <at> ** ** +31-15-2600998 **
**    Delftechpark 26 2628 XH  Delft, The Netherlands. KVK: 27239233    **
*-- BitWizard writes Linux device drivers for any device you may have! --*
The plan was simple, like my brother-in-law Phil. But unlike
Phil, this plan just might work.
Jelle de Jong | 8 Oct 18:28 2014

CF Card wear optimalisation for ext4

Hello everyone,

I been using CF cards for almost more then 7 years now with ext
file-system without any major problems on ALIX boards.

Last year I took 30 other systems in production with ext4 and the CF
cards been dropping out pretty fast, it may have been a bad batch but
I do want to look at it. I don't think the devices writes a lot of IO
(is there a tool that can give me some useful numbers for say 24H or a
week? iotop, atop, sysstat doesn?t seem suited for long term IO write
monitoring, but maybe I am misusing them and can use some help here)

I mount root with the following options:

/dev/disk/by-uuid/09a04c01-64c6-4600-9e22-525667bda3e3 on / type ext4

# dumpe2fs /dev/sda1

Are there kernel options to avoid synchronous disk writes? As
suggested here:

Is there a list of other kernel options I can optimise to limit any cf
wear? The devices don't use

Kind regards

Jelle de Jong
(Continue reading)

Norbert Preining | 27 Sep 14:07 2014

problems with usb stick after suspend and wake up

Dear all,

(please Cc)

I am running latest kernel (3.17-rc6) and I see corruption of an usb3.0
device usb stick. Strange errors, impossibility to mount.

Repeated unplugging and replugging helps sometimes, in all cases
recovery is necessary.

Is this a know problem, a problem of my system
Debian/sid, uptodate, self-compiled kernel
of the suspend program (that initiates the suspend), 
the usb stick and file system, or the USB subsystem?

I happily provide loads of further details about hardware, logs, whatever,
but first I ask before sending tons of useless stuff!?

Any idea?

Thanks a lot


PREINING, Norbert                     
JAIST, Japan                                 TeX Live & Debian Developer
GPG: 0x860CDC13   fp: F7D8 A928 26E3 16A1 9FA0  ACF0 6CAC A448 860C DC13
(Continue reading)

jd1008 | 20 Sep 03:56 2014

Possible bug in mkfs.ext3

I am reporting this on the advice of the Fedora Users Mailing List Member.

This the mailing list exchange outlining the problem with specifying -S 
to mkfs,
and it's subsequent consequences when fsck is run.

I am reporting this per suggestions made to me on the Fedora Users 
Mailing List.

The following is the mailing list exchange:

On 09/18/2014 07:01 PM, Robert Nichols wrote:
> On 09/18/2014 12:37 PM, jd1008 wrote:
>> Is there any other tool that can extract files from a partition that
>> seems to have corrupted superblocks?
>> I tried dumpe2fs, and fsck -b <blockNumber>
>> to no avail. Tried all available block numbers that are listed
>> when original mkfs was done, and it's output was saved.
>> None of the blocks seem to work - all of them have invalid magic.
> Verify that the partition table still appears to be correct.  If it
> is pointing to the wrong starting location, none of the super blocks
> will appear in the expected places. You might see if /testdisk/can
> find any intact super blocks.
> Consider using a hex editor to look at some of the super blocks.
> They should contain the same data.  The data that actually appears
> there might give some clue as to what happened.
(Continue reading)

Bill Cunningham | 25 Aug 21:19 2014


    I hope this is the right list. I have created an ext2 filesystem and 
removed the dir_index feature. I don't know if this kind of experimentation 
is going to help me learn something about filesystems or not. Well what is 
dir_index? Then I ran e2fsck -f -v -pD and the /dev file. Now what did I 
remove? Htree. I guess it can always be put back and it's on an experimental 

    What features separate ext4 from ext3 ? I have noticed too that ext2 
fragments quite a bit.

Bill Cunningham | 17 Aug 21:52 2014

extended filesystems

    I would like to start experiemnting with the ext filesystems. I might
like one day to develop something. :) What files contain the ext4
filesystem. That's what I'm running right now. I like ext 2/3/4 all of them.

    My fedora partition is only 20 GB in size. I don't need huge filesystem
support which is a feature of ext4 I believe. Which feature can I remove to
remove this feature? I know it would be done with tune2fs -O ^ and then the
feature name.

    Why would I want to do this. to learn and I don't think I need it. Too
much overhead.

Roland Olbricht | 17 Aug 19:28 2014

What uses these 50 GB?

Hello everybody,

first of all thank you the development of Ext2/3/4. It works like a 
charm and makes it possible to base applications on it.

However, now I have the first time where I need more information to 
understand the behaviour of a ext4 installation on a 480 GB harddisk.
It holds a database with a size of 355 GB, as said by

"du -m":

355263  /opt/ssd

However, "df" says:

Filesystem      1K-blocks       Used Available Use% Mounted on
/dev/sdc        468346644  409888536  35015532  93% /opt/ssd

I do understand why there is a gap between "Used" plus "Available" and 
"1K-blocks", but I don't understand why "Used" is so much bigger (54 GB 
difference) than what "du -m" indicates.

I can rule out any issues with inodes; "df -i" indicates that less than 
one percent is used.

I tried to understand more details by using "debugfs". I thought I get a 
full list of used blocks with:

(Continue reading)

Ivan Baldo | 7 Jun 01:57 2014

Recommended minimal amount of free space to keep?

     So, LVM is cool, having different partitions for different stuff is 
cool, and of course Ext4 is cool and *reliable*.
     So, we create some logical partitions and put ext4 on them, 
reserving LVM space for growing those partitions or even making new ones 
     The thing is, I would like to keep every filesystem as small as it 
can be, but without degrading the performance too much.
     I guess that having a filesystem 99% full will create too much 
fragmentation and many other issues, but having them only 30% full seems 
like a waste.
     Currently I try to keep them at 70% full utilization but I have not 
based that on anything just guess.
     So, what % hysteresis do you recommend? For example, when they get 
70% full then grow them so that they get 50% full? Other values?
     Thanks for the hints!
     Good day everyone.


Ivan Baldo - ibaldo <at> -
 From Montevideo, Uruguay, at the south of South America.
Freelance programmer and GNU/Linux system administrator, hire me!
Alternatives: ibaldo <at> -
Keith Keller | 31 May 20:56 2014

[long] major problems on fs; e2fsck running out of memory

Hello ext3 list,

I am having an odd issue with one of my filesystems, and I am hoping
someone here can help out.  Yes, I do have backups.  :)  But as is often
the case, it's nice to avoid restoring from backup if possible.  If
there is a more appropriate place for this question please let me know.

After quite a while between reboots, I saw a report on the console that
the filesystem was inconsistent and could not be automatically repaired.
After some aborted tests (which I did not log, unfortunately, I was able
to get this far:

# head fsck.out
fsck from util-linux-ng 2.17.2
/dev/mapper/vg1--sdb-lv_vz contains a file system with errors, check forced.

# time passes, progress bar gets to 51.8% with no problems, then

Pass 1: Checking inodes, blocks, and sizes
Inode 266338321 has imagic flag set.  Clear? yes

Inode 266338321 has a extra size (34120) which is invalid
Fix? yes

Inode 266338321 has compression flag set on filesystem without
compression support.  Clear? yes

# some 150k messages later

Inode 266349409, i_blocks is 94855766560840, should be 0.  Fix? yes
(Continue reading)

Maurice Volaski | 29 May 00:39 2006

[DRBD-user] [Q] What would cause fsck running on a drbd device to just stop?

drbd-0.7.19 under kernel 2.6.17-rc4 is running on a primary node 
standalone. There are 8 resources in the same group. fsck.ext3 -fv is 
being run simultaneously on all of them. Each of the drbd devices are 
running on an lv, which all belong to a single pv. The actual "disk" 
is a hardware RAID connected via SCSI (i.e., the mpt driver).

Five of the fsck finished their tasks successfully and reported no 
problems. The remaining three got "stuck". There was no activity 
either on the physical RAID itself or listed in top. They were just 
listed as "D," uninterruptible sleep. Two of the fscks were at the 
end, giving the final summary information--no problems---for their 
respective filesystems and were stuck at that point. The last one was 
stuck in the first pass. Attempts to kill them failed; even kill -9 
and attempting to shutdown were ignored. I rebooted manually and ran 
the three stuck ones again without a hitch.


Maurice Volaski, mvolaski <at>
Computing Support, Rose F. Kennedy Center
Albert Einstein College of Medicine of Yeshiva University
drbd-user mailing list
drbd-user <at>